mpeg4enc: fix OOB in RasterIntraUpdate

Change the order of checks to avoid OOB read in intraArray

Bug: 176084648
Test: poc in bug
Change-Id: Id6cf902cb7b386760d5f641f05e99ece91621ec5
Merged-In: Id6cf902cb7b386760d5f641f05e99ece91621ec5
1 file changed