ticket 2172 - If "make rpms" fails so will the next make
    
    If "make rpms" fails it doesn't clean up the rpmbuild directory it created.
    The next make-lint will also fail because it finds files under rpmbuild.
    make-lint is invoked by "make rpms", a vicous cycle.
    
    The patch contains two sets of changes
    
    Include "rpmbuild" in the IGNORE_PATHS list of make-lint.
    
    Fix the Makefile to use $(RPMBUILD) consistently, there were a number
    of hardcoded uses of "rpmbuild" as a direcotry.