scsi: qla2xxx: Fix recursive mailbox timeout

This patch prevents user space mailbox request from doing chip reset if the
mailbox timed out. The chip reset is only reserved for the DPC thread to
ensure all mailbox requests are flushed properly. The DPC thread is
responsible for the flushing all MBs and chip reset.

Fixes: b2000805 ("scsi: qla2xxx: Flush mailbox commands on chip reset")
Cc: <stable@ger.kernel.org>
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>