avcodec/ffv1dec: Free tables on init failure

Fixes memleak
Fixes: 07ec1fc3c1cbf2d3edcd7d9b52ca156c/asan_heap-oob_13624c5_491_ecd4720a03e697ba750b235690656c8f.avi

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/ffv1dec.c

@@ -1134,4 +1134,5 @@ AVCodec ff_ffv1_decoder = {
     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
     .capabilities   = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/ |
                       AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_SLICE_THREADS,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP
 };