Refactor jnt_comp into handle_inter_mode
Refactor jnt_comp into handle_inter_mode

Put loops of searching jnt_comp only inside handle_inter_mode
function.

Change-Id: I9508dea64da7e6dfe31fad09aac8679cc855f55f

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