gtp: remove useless initialization

Update b20dc3c6 ("gtp: Allow to create GTP device without FDs") to
remove useless initialization to NULL, sockets are initialized to
non-NULL just a few lines of code after this.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

drivers/net/gtp.c

@@ -1009,8 +1009,8 @@ static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp)
 
 static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[])
 {
-	struct sock *sk1u = NULL;
-	struct sock *sk0 = NULL;
+	struct sock *sk1u;
+	struct sock *sk0;
 
 	sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp);
 	if (IS_ERR(sk0))