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/fib_trie.c b/net/ipv4/fib_trie.c
index 2c7c299..9e4a3e3 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -391,9 +391,9 @@
 	BUG_ON(i >= child_length(tn));
 
 	/* update emptyChildren, overflow into fullChildren */
-	if (n == NULL && chi != NULL)
+	if (!n && chi != NULL)
 		empty_child_inc(tn);
-	if (n != NULL && chi == NULL)
+	if (n != NULL && !chi)
 		empty_child_dec(tn);
 
 	/* update fullChildren */
@@ -528,7 +528,7 @@
 		unsigned long j, k;
 
 		/* An empty child */
-		if (inode == NULL)
+		if (!inode)
 			continue;
 
 		/* A leaf or an internal node with skipped bits */
@@ -1154,7 +1154,7 @@
 			}
 			err = -ENOBUFS;
 			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
-			if (new_fa == NULL)
+			if (!new_fa)
 				goto out;
 
 			fi_drop = fa->fa_info;
@@ -1204,7 +1204,7 @@
 
 	err = -ENOBUFS;
 	new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
-	if (new_fa == NULL)
+	if (!new_fa)
 		goto out;
 
 	new_fa->fa_info = fi;
@@ -1975,7 +1975,7 @@
 		sz += sizeof(struct trie);
 
 	tb = kzalloc(sz, GFP_KERNEL);
-	if (tb == NULL)
+	if (!tb)
 		return NULL;
 
 	tb->tb_id = id;