Remove the dependency in token storing locations

Currently, the tokens for a tile are stored immediately after its
preceding tile, which causes a dependency. This is unnecessary
since we always allocate enough memory for tokens. Removing
the dependency allows token writing done in parallel. This patch
doesn't change encoding result.

Change-Id: I7365a6e5e2c2833eb14377c37e1503c9d0f26543
Merge "Remove the dependency in token storing locations"