Address clang-analyzer warnings about garbage values.
Address clang-analyzer warnings about garbage values.

- False alarm, but surprisingly difficult to convince clang of that. It
  doesn't seem to understand bit shifts very well.

- Only assert and changing LCU_WIDTH>>depth to width was necessary to satisfy
  clang.

- Closes #35.

ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,lu-zero/kvazaar,lu-zero/kvazaar,lu-zero/kvazaar,lu-zero/kvazaar