the existing code in update_boundary info function always set tile
boundary. However, the cdef filter only check tile boundary info but
not the loopfilter_across_tile_boundary_enabled flag. so it always
disable filtering at the tile boundary no matter what the
loopfilter_across_tile_boundary_enabled is.

with this fix, tile boundary info is only set when
the loopfilter_across_tile_boundary_enabled is set to 0. otherwise
it should be ignored.

Change-Id: I67bda08b217dd862bbeef2fd38b7a444b2edf59b