usb: fotg210: fix return value check in fotg210_probe()

usb: fotg210: fix return value check in fotg210_probe()

devm_platform_get_and_ioremap_resource() never returns NULL pointer,
it will return ERR_PTR() when it fails, so replace the check with
IS_ERR().

Fixes: baef5330d35b ("usb: fotg210: Acquire memory resource in core")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230130120633.3342285-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>