Add a pointer check to prevent this smatch warning:
drivers/mmc/host/cavium.c:803 cvm_mmc_request()
error: we previously assumed 'cmd->data' could be null (see line 782)
This is a theoretical fix because MMC_CMD_ADTC seems to imply
that cmd->data is not null. Nevertheless checking cmd->data
before using it improves readability.
Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>