fix(cgpt.py): Fix GPT reserved space calculations.
fix(cgpt.py): Fix GPT reserved space calculations.

The existing code arbitrarily multiplies START_SECTOR by 512 converting
from blocks/sectors to bytes, but blocks was the correct unit to begin
with. Also the secondary GPT area is not considered but that was OK
because the bogus unit conversion oversized our disks by almost 16MB.

Instead of relying on bugs properly reserve 34 sectors at each end of
the disk. (Well, we could get away with only 33 at the end since it
doesn't have a MBR but meh.)

trnubo/scripts,sigma/coreos-scripts,vmware/coreos-scripts,fivethreeo/scripts,mjg59/scripts,bcwaldon/coreos-scripts,endocode/scripts,endocode/scripts,gtank/scripts,mjg59/scripts,coreos/scripts,bcwaldon/coreos-scripts,BugRoger/scripts,smilart/scripts,BugRoger/scripts,gtank/scripts,zhang0137/scripts,marineam/coreos-scripts,endocode/scripts,gtank/scripts,marineam/coreos-scripts,mjg59/scripts,BugRoger/scripts,vmware/coreos-scripts,glevand/coreos--scripts,andrejro/coreos--scripts,crawford/scripts,fivethreeo/scripts,mischief/scripts,bcwaldon/coreos-scripts,smilart/scripts,crawford/scripts,fivethreeo/scripts,coreos/scripts,nicescale/scripts,andrejro/coreos--scripts,marineam/coreos-scripts,mischief/scripts,andrejro/coreos--scripts,zhang0137/scripts,sigma/coreos-scripts,trnubo/scripts,mischief/scripts,nicescale/scripts,nicescale/scripts,crawford/scripts,sigma/coreos-scripts,trnubo/scripts,vmware/coreos-scripts,glevand/coreos--scripts,zhang0137/scripts,smilart/scripts