Harden up guid.h some.
Harden up guid.h some.

Laszlo Ersek rightly pointed out:
1) ZZZZZZZ == 0
2) strtol() should be strtoul()

Signed-off-by: Peter Jones <2e0a021e603479ff81838c00c3b770daca4e0214@redhat.com>

rhinstaller/efivar,rhboot/efivar,CyanogenMod/android_vendor_intel_external_efivar,android-ia/vendor_intel_external_efivar,rhinstaller/efivar,rhboot/efivar,vathpela/efivar-devel