scsi: pmcraid: remove redundant check to see if request_size is less than zero

The 2nd check to see if request_size is less than zero is redundant
because the first check takes error exit path on this condition. So,
since it is redundant, remove it.

Detected by CoverityScan, CID#146149 ("Logically Dead Code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/pmcraid.c

@@ -3770,9 +3770,6 @@ static long pmcraid_ioctl_passthrough(
 			pmcraid_err("couldn't build passthrough ioadls\n");
 			goto out_free_cmd;
 		}
-	} else if (request_size < 0) {
-		rc = -EINVAL;
-		goto out_free_cmd;
 	}
 
 	/* If data is being written into the device, copy the data from user