avcodec/cbs_h2645: Fix leak of SPS VUI extension data

Fixes: VUI extension leak
Fixes: 63004/clusterfuzz-testcase-minimized-ffmpeg_BSF_VVC_METADATA_fuzzer-4928832253329408

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
(cherry picked from commit 3f890fbfd9)

libavcodec/cbs_h2645.c

@@ -1989,7 +1989,17 @@ static const CodedBitstreamUnitTypeDescriptor cbs_h266_unit_types[] = {
     CBS_UNIT_TYPE_INTERNAL_REF(VVC_DCI_NUT, H266RawDCI, extension_data.data),
     CBS_UNIT_TYPE_INTERNAL_REF(VVC_OPI_NUT, H266RawOPI, extension_data.data),
     CBS_UNIT_TYPE_INTERNAL_REF(VVC_VPS_NUT, H266RawVPS, extension_data.data),
-    CBS_UNIT_TYPE_INTERNAL_REF(VVC_SPS_NUT, H266RawSPS, extension_data.data),
+    {
+        .nb_unit_types     = 1,
+        .unit_type.list[0] = VVC_SPS_NUT,
+        .content_type      = CBS_CONTENT_TYPE_INTERNAL_REFS,
+        .content_size      = sizeof(H266RawSPS),
+        .type.ref          = {
+            .nb_offsets = 2,
+            .offsets    = { offsetof(H266RawSPS, extension_data.data),
+                            offsetof(H266RawSPS, vui.extension_data.data) }
+        },
+    },
     CBS_UNIT_TYPE_INTERNAL_REF(VVC_PPS_NUT, H266RawPPS, extension_data.data),
     CBS_UNIT_TYPE_INTERNAL_REF(VVC_PREFIX_APS_NUT, H266RawAPS, extension_data.data),
     CBS_UNIT_TYPE_INTERNAL_REF(VVC_SUFFIX_APS_NUT, H266RawAPS, extension_data.data),