lxcapi_clone: set the right environment variable for mounted fs

If the container is dir-backed, we don't actually mount it (to
support unprivileged use).  So always set the LXC_ROOTFS_MOUNT
to bdev->dest, not to the rootfs path specified in the container
configuration.

This should fix bug http://pad.lv/1253573

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

src/lxc/lxccontainer.c

@@ -2399,7 +2399,7 @@ static int clone_update_rootfs(struct lxc_container *c0,
 		if (setenv("LXC_CONFIG_FILE", conf->rcfile, 1)) {
 			SYSERROR("failed to set environment variable for config path");
 		}
-		if (setenv("LXC_ROOTFS_MOUNT", conf->rootfs.mount, 1)) {
+		if (setenv("LXC_ROOTFS_MOUNT", bdev->dest, 1)) {
 			SYSERROR("failed to set environment variable for rootfs mount");
 		}
 		if (setenv("LXC_ROOTFS_PATH", conf->rootfs.path, 1)) {