block-mount: add missing chunk of previous commit

SVN-Revision: 31050

package/block-mount/files/block.sh

@@ -157,7 +157,7 @@ libmount_find_token() {
 	local token="$1"
 	local value="$2"
 	local device
-	device="$(blkid | grep "$token=\"$value\"" | cut -f1 -d:)"
+	device="$(blkid -w /dev/null -c /dev/null | grep "$token=\"$value\"" | cut -f1 -d:)"
 	echo "$device"
 }