CVE-2022-50846 mmc: via-sdmmc: fix return value check of mmc_add_host()

In the Linux kernel, the following vulnerability has been resolved: mmc: via-sdmmc: fix return value check of mmcaddhost mmcaddhost may return error, if we ignore its return value, it will lead two issues: 1. The memory that allocated in mmcallochost is leaked. 2. In the remove path, mmcremovehos...