Remove the token state array from optimize_b_greedy.
The token state array was carried over from the old optimize_b. With hbd and 64x64 transforms on the array uses 128KB. While the array could be changed to only store tokens, this commit opts to remove it entirely. Improves performance on difficult clips at q20 by roughly 2% with high-bitdepth enabled. Actual speedup should be higher. This change has no impact on metrics. Change-Id: Ib9924092dee30b0f0abcc7850e8bb52d3e891e31