misc-fix: remove a wasted value

This commit merges the fix that remove a wasted value in probability
remaping and subexp coding.

Original libvpx commit:
0f059d6d65dda4f5ce3aa7a62dc7646cbbb6427f

Change-Id: I06668f4ccc189ab13bd4147c12a30da0f15511a1
2 files changed