UPSTREAM: vhost/vsock: fix reset orphans race with close timeout

[ Upstream commit c38f57da428b033f2721b611d84b1f40bde674a8 ]

If a local process has closed a connected socket and hasn't received a
RST packet yet, then the socket remains in the table until a timeout
expires.

When a vhost_vsock instance is released with the timeout still pending,
the socket is never freed because vhost_vsock has already set the
SOCK_DONE flag.

Check if the close timer is pending and let it close the socket.  This
prevents the race which can leak sockets.

Reported-by: Maximilian Riemensberger <riemensberger@cadami.net>
Cc: Graham Whaley <graham.whaley@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 06ec6679fe12cacafce68ab7b509586482a2ae1b)
Bug: 121166534
Test: Ran cuttlefish with android-4.4 + vsock adb tunnel
Signed-off-by: Cody Schuffelen <schuffelen@google.com>
Change-Id: I6b4564aebecc3938b789e56499a3f9b8bbbeb2a1