Merge "Avoid clobbering `errno` from `realpath` call in `__mount`" into main

        if (!android::base::Realpath(source, &real_source)) {

            real_source = source;

        }

        // Clear errno prior to calling `mount`, to avoid clobbering with any errno that

        // may have been set from prior calls (e.g. realpath).

        errno = 0;

        ret = mount(real_source.c_str(), target.c_str(), entry.fs_type.c_str(), mountflags,

                    opts.c_str());

        save_errno = errno;