flashsv: only realloc blocks for version 2

Fixes 10l regression introducing a memleak
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/flashsv.c

@@ -322,6 +322,7 @@ static int flashsv_decode_frame(AVCodecContext *avctx, void *data,
         s->keyframedata = av_realloc(s->keyframedata, avpkt->size);
         memcpy(s->keyframedata, avpkt->data, avpkt->size);
     }
+    if(s->ver == 2)
         s->blocks = av_realloc(s->blocks,
                                 (v_blocks + !!v_part) * (h_blocks + !!h_part)
                                 * sizeof(s->blocks[0]));