Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.

Fixes: 75fa9ea6 ("mmc: add a driver for the Renesas usdhi6rol0 SD/SDIO host controller")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210508020321.1677-1-thunder.leizhen@huawei.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>