Refactor read_and_decode_one_tile_list()
Refactor read_and_decode_one_tile_list()

This patch refactored read_and_decode_one_tile_list(), and moved
the tile list buffer allocation and copying of the decoded tile
out of the function.

Change-Id: I990b806dbc355236db2d69255006e496db179bdb

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom