commit b2c2d237a441318c426509828ebede89e899174d
author James Zern <jzern@google.com> Mon Apr 04 17:44:06 2022
committer James Zern <jzern@google.com> Thu Apr 07 04:56:57 2022
tree cf399f5899b0d524b85aabde97e868f3d14daa30
parent 384e0c32e76ad3f85aca1456e108eaef7eee061a

BackwardReferencesHashChainDistanceOnly: fix segfault on OOM

change CostManager to calloc to avoid frees on undefined pointer
values in CostManagerClear() should the cost_model allocation succeed,
but the cost_manager allocation fail

since:
v0.5.0-93-g3e023c17 Speed-up BackwardReferencesHashChainDistanceOnly.

Tested:
for i in `seq 1 639`; do
  export MALLOC_FAIL_AT=$i
  ./examples/cwebp -m 6 -q 100 -lossless jpeg_file
done

Bug: webp:565
Change-Id: I376d81e6f41eb73529053e9e30c142b4b4f6b45b
(cherry picked from commit a828a59b49d2e3fbc40dc42a6ee6426cd0f2c9dc)
(cherry picked from commit dd80bb43431c222762be47fd92f8a37e032bc2c0)
(cherry picked from commit 4d0964cd0c2b20668d77f965a7e2fbe0b7dcaea4)