Upfront in mmc_rescan() we use the host->rescan_entered flag, to allow
scanning only once for non-removable cards. Therefore, it's also not
possible that we can have a corresponding card bus attached (host->bus_ops
is NULL), when we are scanning non-removable cards.

For this reason, let' drop the check for mmc_card_is_removable() as it's
redundant.
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>