Inside decode_sb_4x4 it should be
"get_tx_type_4x4(mb, y_idx * y_size + x_idx)"
but it was
"get_tx_type_4x4(mb, y_idx * (2 * y_size) + x_idx)".
Also making code of decode_sb_4x4, decode_sb_8x8, and decode_sb_16x16
formatted in the same way.

Change-Id: I15c7bef4fb575f7e9da19f953912324cb35d24dd