ipv4: coding style: comparison for inequality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for non-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/ipmr.c b/net/ipv4/ipmr.c
index a170e4b..c204b72 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -316,7 +316,7 @@
 	unsigned int i;
 
 	mrt = ipmr_get_table(net, id);
-	if (mrt != NULL)
+	if (mrt)
 		return mrt;
 
 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);