hw/sd/sdhci: Don't leak memory region in sdhci_sysbus_realize()

hw/sd/sdhci: Don't leak memory region in sdhci_sysbus_realize()

In sdhci_sysbus_realize() we override the initialization of
s->iomem that sdhci_common_realize() performs. However we
don't destroy the old memory region before reinitializing
it, which means that the memory allocated for mr->name in
memory_region_do_init() is leaked.

Since sdhci_initfn() already initializes s->io_ops to
&sdhci_mmio_ops, always use that in sdhci_common_realize()
and remove the now-unnecessary reinitialization of the
MMIO region from sdhci_sysbus_realize().

Spotted by clang's leak sanitizer.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181204132952.2601-4-peter.maydell@linaro.org