scsi: mpt3sas: Unblock device after controller reset

While issuing any ATA passthrough command to firmware the driver will
block the device. But it will unblock the device only if the I/O
completes through the ISR path. If a controller reset occurs before
command completion the device will remain in blocked state.

Make sure we unblock the device following a controller reset if an ATA
passthrough command was queued.

[mkp: clarified patch description]

Cc: <stable@vger.kernel.org> # v4.4+
Fixes: ac6c2a93bd07 ("mpt3sas: Fix for SATA drive in blocked state, after diag reset")
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>