Fixes check for Darwin Kernel in Makefile
Fixes check for Darwin Kernel in Makefile

The kernel needed to be set outside of the ifeq

jkhoogland/cppitertools,jkhoogland/cppitertools,ryanhaining/cppitertools,jkhoogland/cppitertools,tempbottle/cppitertools,tempbottle/cppitertools,tempbottle/cppitertools,ryanhaining/cppitertools,ryanhaining/cppitertools