TBR: fix up arm portion of update_bootloaders
TBR: fix up arm portion of update_bootloaders

Removed two errant locals in the arm section

TEST=manual build_image on tegra1-dev-board
BUG=none
TBR=fes

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