In case of error, the function devm_ioremap_resource() 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 <weiyongjun1@huawei.com>
Acked-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>