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_rules.c b/net/ipv4/fib_rules.c
index 8162dd8..5615198 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -153,7 +153,7 @@
 	u32 id;
 
 	for (id = 1; id <= RT_TABLE_MAX; id++)
-		if (fib_get_table(net, id) == NULL)
+		if (!fib_get_table(net, id))
 			return fib_new_table(net, id);
 	return NULL;
 }
@@ -184,7 +184,7 @@
 			struct fib_table *table;
 
 			table = fib_empty_table(net);
-			if (table == NULL) {
+			if (!table) {
 				err = -ENOBUFS;
 				goto errout;
 			}