adjust fstab and mount device param

image/overlay/etc/fstab

@@ -1,5 +1,4 @@
 # /etc/fstab: static file system information
 #
 # <file system>	<mount point>	<type>		<options>		<dump>	<pass>
-/dev/root	/		ext4		rw,noatime		0	1
-data		/data		virtiofs	rw,noatime,_netdev	0	0
+/dev/vdb	/data		ext4	rw,noatime  0   1