When initializing sd or sdio card, we get struct mmc_card
from mmc_alloc_card which allocates it by kzalloc. So we don't
need another memset while decoding cid.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>