Fix tune vmaf build

Change-Id: I50a57bba4643c6f83a140f670ee0f1d5c1f0573e

apps/aomenc.c

diff --git a/apps/aomenc.c b/apps/aomenc.c
index 2756a4f..4908058 100644
--- a/apps/aomenc.c
+++ b/apps/aomenc.c
@@ -1004,7 +1004,7 @@
       config->cfg.tile_height_count =
           arg_parse_list(&arg, config->cfg.tile_heights, MAX_TILE_HEIGHTS);
 #if CONFIG_TUNE_VMAF
-    } else if (arg_match(&arg, &vmaf_model_path, argi)) {
+    } else if (arg_match(&arg, &g_av1_codec_arg_defs.vmaf_model_path, argi)) {
       config->vmaf_model_path = arg.val;
 #endif
     } else if (arg_match(&arg, &g_av1_codec_arg_defs.use_fixed_qp_offsets,