scsi: aacraid: Add a missing iounmap call

Add a missing resource cleanup in _aac_reset_adapter.

Link: https://lore.kernel.org/r/20200926150015.6187-1-thenzl@redhat.com


Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>