The debugfs_create_dir() function returns error pointers.
It never returns NULL. So use IS_ERR() to check it.
Signed-off-by: Yang Ruibin <11162571@vivo.com>
Link: https://patch.msgid.link/20240821083911.3411-1-11162571@vivo.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>