ALSA: ctxfi - Simple code clean up

- replace NULL == xxx with !xxx
- replace NULL != xxx with xxx
- similar trivial cleanups

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/ctxfi/ctamixer.c b/sound/pci/ctxfi/ctamixer.c
index a7f4a67..fee35cf 100644
--- a/sound/pci/ctxfi/ctamixer.c
+++ b/sound/pci/ctxfi/ctamixer.c
@@ -63,7 +63,7 @@
 	hw = amixer->rsc.hw;
 	hw->amixer_set_mode(amixer->rsc.ctrl_blk, AMIXER_Y_IMMEDIATE);
 	amixer->input = rsc;
-	if (NULL == rsc)
+	if (!rsc)
 		hw->amixer_set_x(amixer->rsc.ctrl_blk, BLANK_SLOT);
 	else
 		hw->amixer_set_x(amixer->rsc.ctrl_blk,
@@ -99,7 +99,7 @@
 
 	hw = amixer->rsc.hw;
 	amixer->sum = sum;
-	if (NULL == sum) {
+	if (!sum) {
 		hw->amixer_set_se(amixer->rsc.ctrl_blk, 0);
 	} else {
 		hw->amixer_set_se(amixer->rsc.ctrl_blk, 1);
@@ -124,20 +124,20 @@
 
 	/* Program master and conjugate resources */
 	amixer->rsc.ops->master(&amixer->rsc);
-	if (NULL != input)
+	if (input)
 		input->ops->master(input);
 
-	if (NULL != sum)
+	if (sum)
 		sum->rsc.ops->master(&sum->rsc);
 
 	for (i = 0; i < amixer->rsc.msr; i++) {
 		hw->amixer_set_dirty_all(amixer->rsc.ctrl_blk);
-		if (NULL != input) {
+		if (input) {
 			hw->amixer_set_x(amixer->rsc.ctrl_blk,
 						input->ops->output_slot(input));
 			input->ops->next_conj(input);
 		}
-		if (NULL != sum) {
+		if (sum) {
 			hw->amixer_set_sadr(amixer->rsc.ctrl_blk,
 						sum->rsc.ops->index(&sum->rsc));
 			sum->rsc.ops->next_conj(&sum->rsc);
@@ -147,10 +147,10 @@
 		amixer->rsc.ops->next_conj(&amixer->rsc);
 	}
 	amixer->rsc.ops->master(&amixer->rsc);
-	if (NULL != input)
+	if (input)
 		input->ops->master(input);
 
-	if (NULL != sum)
+	if (sum)
 		sum->rsc.ops->master(&sum->rsc);
 
 	return 0;
@@ -303,7 +303,7 @@
 
 	*ramixer_mgr = NULL;
 	amixer_mgr = kzalloc(sizeof(*amixer_mgr), GFP_KERNEL);
-	if (NULL == amixer_mgr)
+	if (!amixer_mgr)
 		return -ENOMEM;
 
 	err = rsc_mgr_init(&amixer_mgr->mgr, AMIXER, AMIXER_RESOURCE_NUM, hw);
@@ -456,7 +456,7 @@
 
 	*rsum_mgr = NULL;
 	sum_mgr = kzalloc(sizeof(*sum_mgr), GFP_KERNEL);
-	if (NULL == sum_mgr)
+	if (!sum_mgr)
 		return -ENOMEM;
 
 	err = rsc_mgr_init(&sum_mgr->mgr, SUM, SUM_RESOURCE_NUM, hw);