Avoid using an anonymous union.

Change-Id: I5744269a35e2d696ecf40c1665efd572bfc9b6cb

vpx/internal/vpx_codec_internal.h

diff --git a/vpx/internal/vpx_codec_internal.h b/vpx/internal/vpx_codec_internal.h
index dcb451d..9cde426 100644
--- a/vpx/internal/vpx_codec_internal.h
+++ b/vpx/internal/vpx_codec_internal.h
@@ -321,7 +321,7 @@
     {
         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

diff --git a/vpx/src/vpx_decoder.c b/vpx/src/vpx_decoder.c
index 27049a5..7b78e5c 100644
--- a/vpx/src/vpx_decoder.c
+++ b/vpx/src/vpx_decoder.c
@@ -160,7 +160,7 @@
         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 @@
         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;
     }