server: process STOP/QUIT commands out-of-line

server: process STOP/QUIT commands out-of-line

At the end of a job, the stats entries are queued up for
out-of-line transmission, but we immediately queue a client
STOP+QUIT command right after that. If the command handling
loop doesn't wakeup and process the stats commands before we
process the STOP+QUIT inline, then we lose the stats output
from those commands. The result is that the client won't see
the job output from that job, or the "All clients" output.

We should impose proper ordering for all commands, but this
is a quick fix to ensure that we don't hit the above mentioned
but. For other commands we don't care about ordering between
inline and out-of-line commands, so it's likely good enough
to carry us forward.

Reported-by: Jeff Furlong <jeff.furlong@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>