mptcp: Fix code formatting

checkpatch.pl had a few complaints in the last set of MPTCP patches:

ERROR: code indent should use tabs where possible
+^I         subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped);$

CHECK: Comparison to NULL could be written "!new_ctx"
+	if (new_ctx == NULL) {

ERROR: "foo * bar" should be "foo *bar"
+static const struct proto_ops * tcp_proto_ops(struct sock *sk)

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/subflow.c

@@ -773,7 +773,7 @@ static void subflow_ulp_clone(const struct request_sock *req,
 	}
 
 	new_ctx = subflow_create_ctx(newsk, priority);
-	if (new_ctx == NULL) {
+	if (!new_ctx) {
 		subflow_ulp_fallback(newsk, old_ctx);
 		return;
 	}