scsi: ses: Fix unsigned comparison with less than zero

Fix the following coccicheck warning:

./drivers/scsi/ses.c:137:10-16: WARNING: Unsigned expression compared
with zero: result > 0.

Link: https://lore.kernel.org/r/1632477113-90378-1-git-send-email-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ses.c

@@ -118,7 +118,7 @@ static int ses_recv_diag(struct scsi_device *sdev, int page_code,
 static int ses_send_diag(struct scsi_device *sdev, int page_code,
 			 void *buf, int bufflen)
 {
-	u32 result;
+	int result;
 
 	unsigned char cmd[] = {
 		SEND_DIAGNOSTIC,