cmdlib.sh: fix a bug of restart_daemon

start should be replaced with restart in restart_daemon().

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
diff --git a/testcases/lib/cmdlib.sh b/testcases/lib/cmdlib.sh
index 7819cb7..b1ea15e 100644
--- a/testcases/lib/cmdlib.sh
+++ b/testcases/lib/cmdlib.sh
@@ -198,8 +198,8 @@
 restart_daemon()
 {
 	if [ $HAVE_SYSTEMCTL -eq 1 ]; then
-		systemctl start $1.service > /dev/null 2>&1
+		systemctl restart $1.service > /dev/null 2>&1
 	else
-		service $1 start > /dev/null 2>&1
+		service $1 restart > /dev/null 2>&1
 	fi
 }