[SCSI] qla2xxx: Fix for a multiqueue bug in CPU affinity mode

Hold the hardware lock while do the response completion in work queue threads as
it involves sharing a common request queue among multiple threads.

Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>