avformat/flvdec: increase buffer size for parsing metadata string key

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/flvdec.c

@@ -558,7 +558,7 @@ static int flv_read_metabody(AVFormatContext *s, int64_t next_pos)
     int i;
     // only needs to hold the string "onMetaData".
     // Anything longer is something we don't want.
-    char buffer[11];
+    char buffer[32];
 
     astream = NULL;
     vstream = NULL;