lavc/hevc_parser: report detailed log when missing picture occurs

Report the detailed log with buf_size in parse_nal_units to provide
more information when picture could not be found.

Match the behaviour in h264_parser.
Signed-off-by: Linjie Fu <linjie.fu@intel.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/hevc_parser.c

@@ -239,7 +239,7 @@ static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
         }
     }
     /* didn't find a picture! */
-    av_log(avctx, AV_LOG_ERROR, "missing picture in access unit\n");
+    av_log(avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
     return -1;
 }