mmc: block: Make card_busy_detect() a bit more generic

To prepare for more users of card_busy_detect(), let's drop the struct
request * as an in-parameter and convert to log the error message via
dev_err() instead of pr_err().

Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>