Only memset for palettes of 16 elements.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@20377 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/pcx.c

@@ -71,6 +71,7 @@ static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen)
 
     for (i=0; i<pallen; i++)
         *dst++ = bytestream_get_be24(src);
+    if (pallen < 256)
     memset(dst, 0, (256 - pallen) * sizeof(*dst));
 }