simpleperf: just use _Exit directly.

We don't actually need the quick_exit() machinery because we weren't
setting any at_quick_exit() handlers, so just call _Exit() directly.

This will let us remove the Mac/Windows quick_exit() implementation from
libbase (and will let simpleperf exit just a little bit quicker).

Test: treehugger
Change-Id: I4ce74cb80acc744721cf367930ca3e577b8fc614
1 file changed