When call function devm_platform_ioremap_resource(), we should use IS_ERR()
to check the return value
and return PTR_ERR() if failed.
Fixes: 893a66d34298 ("usb: bdc: use devm_platform_ioremap_resource() to simplify code")[...]
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>