Set up frame context using next_ref_frame_map

BUG: oss-fuzz:11523
Change-Id: Idec84e85f39fa6e2205853763002898b6ab1b410

av1/decoder/decodeframe.c

diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index d17e605..f9de800 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -4755,7 +4755,8 @@
   generate_next_ref_frame_map(pbi);
 
   // Reload the adapted CDFs from when we originally coded this keyframe
-  *cm->fc = frame_bufs[cm->ref_frame_map[existing_frame_idx]].frame_context;
+  *cm->fc =
+      frame_bufs[cm->next_ref_frame_map[existing_frame_idx]].frame_context;
 }
 
 static INLINE void reset_frame_buffers(AV1_COMMON *cm) {