mptcp: drop redundant test in move_skbs_to_msk()

Currently we check the msk state to avoid enqueuing new
skbs at msk shutdown time.

Such test is racy - as we can't acquire the msk socket lock -
and useless, as the caller already checked the subflow
field 'disposable', covering the same scenario in a race
free manner - read and updated under the ssk socket lock.

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

net/mptcp/protocol.c

@@ -686,9 +686,6 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
 	struct sock *sk = (struct sock *)msk;
 	unsigned int moved = 0;
 
-	if (inet_sk_state_load(sk) == TCP_CLOSE)
-		return false;
-
 	__mptcp_move_skbs_from_subflow(msk, ssk, &moved);
 	__mptcp_ofo_queue(msk);
 	if (unlikely(ssk->sk_err)) {