Refactoring vad_filterbank

Made internal function LogOfEnergy() more efficient.
Includes
- Name change "vector" -> "data"
- Complete refactor of LogOfEnergy()
- Removed lint warning

Major changes:
* Removed unnecessary variables
* Reduced number of shifts
* Removed one norm calculation


TEST=vad_unittests, audioproc_unittest
Review URL: http://webrtc-codereview.appspot.com/347004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1407 4adac7df-926f-26a2-2b94-8c16560cd09d
3 files changed