kmem_cache_free() with NULL is not allowed. But it may happen
if out of memory error is triggered in sysfs_new_dirent().
This patch fixes that error handling.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>