scsi: aacraid: Fix an oops in error handling

If the memdup_user() function fails then it results in an Oops in the
error handling code when we try to kfree() and error pointer.

Link: https://lore.kernel.org/r/20200513093703.GB347693@mwanda


Fixes: 8d925b1f ("scsi: aacraid: Use memdup_user() as a cleanup")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>