mptcp: avoid unneeded address copy

[ Upstream commit 2bb9a37 ]

In the syn_recv fallback path, the msk is unused. We can skip
setting the socket address.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 7e8b88e ("mptcp: consolidate passive msk socket initialization")
Signed-off-by: Sasha Levin <sashal@kernel.org>

net/mptcp/subflow.c

@@ -759,8 +759,6 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 				goto dispose_child;
 			}
 
-			if (new_msk)
-				mptcp_copy_inaddrs(new_msk, child);
 			mptcp_subflow_drop_ctx(child);
 			goto out;
 		}