Add scsi_done_direct() which behaves like scsi_done() except that it
invokes blk_mq_complete_request_direct() in order to complete the request.

Callers from process context can complete the request directly instead
waking ksoftirqd.

Link: https://lore.kernel.org/r/Yfw7JaszshmfYa1d@flowReviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>