Blender Git Loki

Cycles: Cleanup, style and unused arguments

- Some arguments were inapproriatry tagged as unused
using (void)foo semantic.

Only use such semantic in tricky casses, when something
needs to be ignored in release builds or something is
dependent on tricky ifndef policy.

For rest of the cases just use void foo(int /bar*/)
semantic, which ensures variable is not used. Solves
confusion and code running out of sync with later
development.

- Used proper unused semantic to some arguments.

- Added braces to make code easier to follow, tricky
indentation with ifdef, uh.