mmc: core: convert comma to semicolon

Replace a comma between expression statements by a semicolon.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Link: https://lore.kernel.org/r/20201216131737.14883-1-zhengyongjun3@huawei.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>