ipv4: coding style: comparison for equality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for NULL pointer is done as x == NULL and sometimes as !x. !x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 3ef30cf..a170e4b 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -189,7 +189,7 @@
 	}
 
 	mrt = ipmr_get_table(rule->fr_net, rule->table);
-	if (mrt == NULL)
+	if (!mrt)
 		return -EAGAIN;
 	res->mrt = mrt;
 	return 0;
@@ -253,7 +253,7 @@
 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
 
 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
-	if (mrt == NULL) {
+	if (!mrt) {
 		err = -ENOMEM;
 		goto err1;
 	}
@@ -320,7 +320,7 @@
 		return mrt;
 
 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
-	if (mrt == NULL)
+	if (!mrt)
 		return NULL;
 	write_pnet(&mrt->net, net);
 	mrt->id = id;
@@ -422,7 +422,7 @@
 			dev->flags |= IFF_MULTICAST;
 
 			in_dev = __in_dev_get_rtnl(dev);
-			if (in_dev == NULL)
+			if (!in_dev)
 				goto failure;
 
 			ipv4_devconf_setall(in_dev);
@@ -506,7 +506,7 @@
 
 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
 
-	if (dev == NULL)
+	if (!dev)
 		return NULL;
 
 	dev_net_set(dev, net);
@@ -762,7 +762,7 @@
 	case 0:
 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
-			if (dev && __in_dev_get_rtnl(dev) == NULL) {
+			if (dev && !__in_dev_get_rtnl(dev)) {
 				dev_put(dev);
 				return -EADDRNOTAVAIL;
 			}
@@ -1008,7 +1008,7 @@
 
 	rcu_read_lock();
 	mroute_sk = rcu_dereference(mrt->mroute_sk);
-	if (mroute_sk == NULL) {
+	if (!mroute_sk) {
 		rcu_read_unlock();
 		kfree_skb(skb);
 		return -EINVAL;
@@ -1161,7 +1161,7 @@
 		return -EINVAL;
 
 	c = ipmr_cache_alloc();
-	if (c == NULL)
+	if (!c)
 		return -ENOMEM;
 
 	c->mfc_origin = mfc->mfcc_origin.s_addr;
@@ -1283,7 +1283,7 @@
 		return -EOPNOTSUPP;
 
 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	if (optname != MRT_INIT) {
@@ -1446,7 +1446,7 @@
 		return -EOPNOTSUPP;
 
 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	if (optname != MRT_VERSION &&
@@ -1492,7 +1492,7 @@
 	struct mr_table *mrt;
 
 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	switch (cmd) {
@@ -1566,7 +1566,7 @@
 	struct mr_table *mrt;
 
 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	switch (cmd) {
@@ -1701,7 +1701,7 @@
 	struct flowi4 fl4;
 	int    encap = 0;
 
-	if (vif->dev == NULL)
+	if (!vif->dev)
 		goto out_free;
 
 #ifdef CONFIG_IP_PIMSM
@@ -1992,7 +1992,7 @@
 
 	/* already under rcu_read_lock() */
 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
-	if (cache == NULL) {
+	if (!cache) {
 		int vif = ipmr_find_vif(mrt, skb->dev);
 
 		if (vif >= 0)
@@ -2003,13 +2003,13 @@
 	/*
 	 *	No usable cache entry
 	 */
-	if (cache == NULL) {
+	if (!cache) {
 		int vif;
 
 		if (local) {
 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 			ip_local_deliver(skb);
-			if (skb2 == NULL)
+			if (!skb2)
 				return -ENOBUFS;
 			skb = skb2;
 		}
@@ -2068,7 +2068,7 @@
 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
 	read_unlock(&mrt_lock);
 
-	if (reg_dev == NULL)
+	if (!reg_dev)
 		return 1;
 
 	skb->mac_header = skb->network_header;
@@ -2198,18 +2198,18 @@
 	int err;
 
 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	rcu_read_lock();
 	cache = ipmr_cache_find(mrt, saddr, daddr);
-	if (cache == NULL && skb->dev) {
+	if (!cache && skb->dev) {
 		int vif = ipmr_find_vif(mrt, skb->dev);
 
 		if (vif >= 0)
 			cache = ipmr_cache_find_any(mrt, daddr, vif);
 	}
-	if (cache == NULL) {
+	if (!cache) {
 		struct sk_buff *skb2;
 		struct iphdr *iph;
 		struct net_device *dev;
@@ -2267,7 +2267,7 @@
 	int err;
 
 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	rtm = nlmsg_data(nlh);
@@ -2332,7 +2332,7 @@
 
 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
 			GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
@@ -2447,7 +2447,7 @@
 	struct mr_table *mrt;
 
 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return ERR_PTR(-ENOENT);
 
 	iter->mrt = mrt;
@@ -2566,7 +2566,7 @@
 	struct mr_table *mrt;
 
 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
-	if (mrt == NULL)
+	if (!mrt)
 		return ERR_PTR(-ENOENT);
 
 	it->mrt = mrt;