net/smc: fix refcounting for non-blocking connect()

If a nonblocking socket is immediately closed after connect(),
the connect worker may not have started. This results in a refcount
problem, since sock_hold() is called from the connect worker.
This patch moves the sock_hold in front of the connect worker
scheduling.

Reported-by:  <syzbot+4c063e6dea39e4b79f29@syzkaller.appspotmail.com>
Fixes: 50717a37

 ("net/smc: nonblocking connect rework")
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>