Merge commit '771656bd'

* commit '771656bd':
  libvpxenc: clean memory on error

Conflicts:
	libavcodec/libvpxenc.c

See: 104b1d9eMerged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libvpxenc.c

@@ -644,7 +644,7 @@ static int queue_frames(AVCodecContext *avctx, AVPacket *pkt_out,
                     av_log(avctx, AV_LOG_ERROR,
                            "Data buffer alloc (%"SIZE_SPECIFIER" bytes) failed\n",
                            cx_frame->sz);
-                    av_free(cx_frame);
+                    av_freep(&cx_frame);
                     return AVERROR(ENOMEM);
                 }
                 memcpy(cx_frame->buf, pkt->data.frame.buf, pkt->data.frame.sz);