Avoid using an anonymous union.

Change-Id: I5744269a35e2d696ecf40c1665efd572bfc9b6cb

vpx/internal/vpx_codec_internal.h

@@ -321,7 +321,7 @@ typedef struct vpx_codec_priv_cb_pair
     {
         vpx_codec_put_frame_cb_fn_t    put_frame;
         vpx_codec_put_slice_cb_fn_t    put_slice;
-    };
+    } u;
     void                            *user_priv;
 } vpx_codec_priv_cb_pair_t;
 

vpx/src/vpx_decoder.c

@@ -160,7 +160,7 @@ vpx_codec_err_t vpx_codec_register_put_frame_cb(vpx_codec_ctx_t             *ctx
         res = VPX_CODEC_ERROR;
     else
     {
-        ctx->priv->dec.put_frame_cb.put_frame = cb;
+        ctx->priv->dec.put_frame_cb.u.put_frame = cb;
         ctx->priv->dec.put_frame_cb.user_priv = user_priv;
         res = VPX_CODEC_OK;
     }
@@ -182,7 +182,7 @@ vpx_codec_err_t vpx_codec_register_put_slice_cb(vpx_codec_ctx_t             *ctx
         res = VPX_CODEC_ERROR;
     else
     {
-        ctx->priv->dec.put_slice_cb.put_slice = cb;
+        ctx->priv->dec.put_slice_cb.u.put_slice = cb;
         ctx->priv->dec.put_slice_cb.user_priv = user_priv;
         res = VPX_CODEC_OK;
     }