Fixes: OOM testcase
Fixes: 51527/clusterfuzz-testcase-minimized-ffmpeg_dem_LAF_fuzzer-5453663505612800
OOM can still happen after this as an arbitrary sized block is allocated and read
this would require a redesign or some limit on the sample rate.
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
