#12 Do not guard sys/quota.h sys/swap.h and sys/reboot.h with __GLIBC__

[Khem Raj]

We have these headers on other libc implementations as well, therefore there is no need to conditionally include them with GLIBC define. This helps fixing the build with musl where the reboot() funciton declaration is in sys/reboot.h but its not included due to this conditional inclusion.

[Paul Crawford]

Now applied