scsi: hpsa: Check for null device pointers

scsi: hpsa: Check for null device pointers

A device can be deleted causing NULL pointer issues.

Reviewed-by: Scott Benesh <scott.benesh@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Orabug: 25605941
(cherry picked from commit d49c2077c03d70a59e3063c7d33f00172491ae31)
Signed-off-by: Jack Vogel <jack.vogel@oracle.com>