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/tcp.c b/net/ipv4/tcp.c
index dbd51ce..5bd809b 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1047,7 +1047,7 @@
 
 	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
 				   sk->sk_allocation);
-	if (unlikely(tp->fastopen_req == NULL))
+	if (unlikely(!tp->fastopen_req))
 		return -ENOBUFS;
 	tp->fastopen_req->data = msg;
 	tp->fastopen_req->size = size;