mmc: sdhci-of-dwcmshc: fix error return code in dwcmshc_probe()

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

Fixes: c2c4da37837e ("mmc: sdhci-of-dwcmshc: add rockchip platform support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210323112956.1016884-1-weiyongjun1@huawei.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>