scsi: ibmvfc: Complete commands outside the host/queue lock

scsi: ibmvfc: Complete commands outside the host/queue lock

Drain the command queue and place all commands on a completion list.
Perform command completion on that list outside the host/queue locks.
Further, move purged command compeletions outside the host_lock as well.

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Brian King <[email protected]>
Signed-off-by: Tyrel Datwyler <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>