vd_lavc: put vaapi before vdpau in autoprobe order

--hwdec=auto-copy was preferring vdpau over vaapi. In the HEVC 10 bit
case, this also led to hardware decoding not being enabled. (Probably
because the probing can't start over after enabling hw decoding fails at
runtime, or something like that.)

Possible that this subtly breaks on some setups. You can't always win.

video/decode/vd_lavc.c

@@ -223,10 +223,10 @@ static const char *const hwdec_autoprobe_order[] = {
     "d3d11va-copy",
     "nvdec",
     "nvdec-copy",
-    "vdpau",
-    "vdpau-copy",
     "vaapi",
     "vaapi-copy",
+    "vdpau",
+    "vdpau-copy",
     0
 };