clean_workspace: correct flag and make command
Created by: prwolfe
the --force-clean flag had two conflicting names and the final make command (make -C %s clean) failed in an infinite recursion. I just modified it to cd to the directory first and then run 'make clean'
@trilinos/framework
How Has This Been Tested?
tested with the unit tests and I created a directory, built and used both the date and force options to clean it.