Allow callers of sysfs_remove_link() to pass a NULL kobj, in which case
sysfs_root will be used as the parent directory. This allows us to tear down
top level symlinks created via sysfs_create_link(), which already has
similar handling of a NULL parent object.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>