Fix bug in motion search

The maximum possible MV in 1/8 pel units is (1<<11), which could
cause mvcost out of its range that is 1023. Change maximum
possible MV in 1/8 pel units to (1<<11)-8 will fix this problem.

Change-Id: I5788ed1de773f66658c14f225fb4ab5b1679b74b
2 files changed