Fix tests/sys/kqueue without -fcommon and bump WARNS

[arichardson]

Summary

While touching these files also add lots of static to fix the build without
settings WARNS to 2.

Test Plan

compiles

[arichardson]

fix two more warnings that I missed

[kevans]

Crap, sorry, I already committed part of this because I forgot this review hit my inbox. =(

kqfd is actually meant to be shared throughout libkqueue at the moment -- note, e.g., test_no_kevents that's checking a kqfd and being called from other CUs. I removed all of the other kqfd declarations, so this will hit some kind of tedious merge conflicts when applied... the rest of the patch LGTM, so if you'd like I can rebase it forward and commit the WARNS fixes if you'd rather not deal with the mess I've left.

[arichardson]

In D24296#535609, @kevans wrote:

Crap, sorry, I already committed part of this because I forgot this review hit my inbox. =(

kqfd is actually meant to be shared throughout libkqueue at the moment -- note, e.g., test_no_kevents that's checking a kqfd and being called from other CUs. I removed all of the other kqfd declarations, so this will hit some kind of tedious merge conflicts when applied... the rest of the patch LGTM, so if you'd like I can rebase it forward and commit the WARNS fixes if you'd rather not deal with the mess I've left.

You're right, I just fixed the warning without seeing that it's meant to be shared. I'll rebase the warning fixes on top of you changes. Should be trivial.

[arichardson]

rebase