proxy: log with virgl_logv

We lose the "proxy: " prefix, but we can live with it.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Ryan Neph <ryanneph@google.com>
Reviewed-by: Yiwei Zhang <zzyiwei@chromium.org>

src/proxy/proxy_common.c

@@ -14,12 +14,7 @@ void
 proxy_log(const char *fmt, ...)
 {
    va_list va;
-
    va_start(va, fmt);
-
-   fprintf(stderr, "proxy: ");
-   vfprintf(stderr, fmt, va);
-   fprintf(stderr, "\n");
-
+   virgl_logv(fmt, va);
    va_end(va);
 }