CVE-2023-54204 mmc: sunplus: fix return value check of mmc_add_host()

In the Linux kernel, the following vulnerability has been resolved: mmc: sunplus: fix return value check of mmcaddhost mmcaddhost may return error, if we ignore its return value, 1. the memory allocated in mmcallochost will be leaked 2. null-ptr-deref will happen when calling mmcremovehost in...