Fixed use of early breakout in vp8_pick_intra4x4mby_modes

Index i is used to detect early breakout from the first loop, but
its value is lost due to reuse in the second for loop. I moved
the position of the second loop and did some format cleanup.

Change-Id: I02780eae1bd89df4b6c000fb8a018b0837aac2e5