include/linux/nodemask.h: create next_node_in() helper

Lots of code does

	node = next_node(node, XXX);
	if (node == MAX_NUMNODES)
		node = first_node(XXX);

so create next_node_in() to do this and use it in various places.

[mhocko@suse.com: use next_node_in() helper]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Hui Zhu <zhuhui@xiaomi.com>
Cc: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1902956..611cc69 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2591,13 +2591,7 @@
 
 static int cpuset_spread_node(int *rotor)
 {
-	int node;
-
-	node = next_node(*rotor, current->mems_allowed);
-	if (node == MAX_NUMNODES)
-		node = first_node(current->mems_allowed);
-	*rotor = node;
-	return node;
+	return *rotor = next_node_in(*rotor, current->mems_allowed);
 }
 
 int cpuset_mem_spread_node(void)