Simplify and fix available memory calculation to fix shell script errors on boot. Fix spelling error in comment
Simplify and fix available memory calculation to fix shell script errors on boot.
Fix spelling error in comment

ch1c4um/pfsense,phil-davis/pfsense,jxmx/pfsense,jxmx/pfsense,ptorsten/pfsense,dennypage/pfsense,ch1c4um/pfsense,brunostein/pfsense,dennypage/pfsense,ch1c4um/pfsense,NewEraCracker/pfsense,NewEraCracker/pfsense,NOYB/pfsense,dennypage/pfsense,BlackstarGroup/pfsense,jxmx/pfsense,pfsense/pfsense,NOYB/pfsense,brunostein/pfsense,brunostein/pfsense,pfsense/pfsense,NewEraCracker/pfsense,phil-davis/pfsense,ch1c4um/pfsense,BlackstarGroup/pfsense,NOYB/pfsense,NewEraCracker/pfsense,pfsense/pfsense,BlackstarGroup/pfsense,ptorsten/pfsense,BlackstarGroup/pfsense,phil-davis/pfsense,pfsense/pfsense,ptorsten/pfsense,dennypage/pfsense,phil-davis/pfsense