mmc: sdhci-of-aspeed: remove unneeded variables

The variable 'dead' is redundant, let's remove it.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230727070051.17778-32-frank.li@vivo.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>