This fixes a compiler-reported divide-by-zero when HZ < 100.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -63,7 +63,7 @@ static int scsi_get_bus(request_queue_t 
 
 static int sg_get_timeout(request_queue_t *q)
 {
-	return q->sg_timeout / (HZ / USER_HZ);
+	return q->sg_timeout / max(1,(HZ / USER_HZ));
 }
 
 static int sg_set_timeout(request_queue_t *q, int __user *p)