ath: fix all -Wunused-but-set-variable warnings

[svmhdvn]

Patch set attached in the following manner:

[PATCH 1/8] ath: fix DEBUG print varargs macros to handle unused parameters This clears out a lot of unused-but-set warnings cleanly while avoiding the #ifdef DEBUG pattern

[PATCH 2..6/8] These are non-trivial changes that need a closer review to ensure no breaking changes.

[PATCH 7/8] ath_hal: fix all remaining trivial -wunused-but-set-variable warnings These are all the remaining (trivial) changes.

[PATCH 8/8] build: ath: re-enable -wunused-but-set-variable in ATH_C Once all warnings are cleaned up, the ${NO_WUNUSED_BUT_SET_VARIABLE} can be removed safely.

[erikarn]

hi,

some of the bits in here are good, but a lot of them remove diagnostics that are useful. I'll spend some time cherry-picking from this diff when I'm finished with my current 802.11 diff stack (as I also have some other ath diffs to land!)

[bsdimp]

Any progress on reply to @erikarn 's comments of 3 weeks ago?

[svmhdvn]

@erikarn which diagnostics are you referring to? I've tried to maintain as much as possible, but I'll make the necessary changes.