In case of error, the function kthread_run() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>