selinux: Unify for- and while-loop style

Replace "thing != NULL" comparisons with just "thing" to make
the code look more uniform (mixed styles were used even in the
same source file).

Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c
index 2e7788e..933e735 100644
--- a/security/selinux/ss/hashtab.c
+++ b/security/selinux/ss/hashtab.c
@@ -81,7 +81,7 @@
 
 	hvalue = h->hash_value(h, key);
 	cur = h->htable[hvalue];
-	while (cur != NULL && h->keycmp(h, key, cur->key) > 0)
+	while (cur && h->keycmp(h, key, cur->key) > 0)
 		cur = cur->next;
 
 	if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
@@ -100,7 +100,7 @@
 
 	for (i = 0; i < h->size; i++) {
 		cur = h->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			temp = cur;
 			cur = cur->next;
 			kfree(temp);
@@ -127,7 +127,7 @@
 
 	for (i = 0; i < h->size; i++) {
 		cur = h->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			ret = apply(cur->key, cur->datum, args);
 			if (ret)
 				return ret;