In case of error, the function device_create_with_groups()
returns ERR_PTR() and never returns NULL. The NULL test in
the return value check should be replaced with IS_ERR().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NFrank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>