fix to run Z->mumu alignment validation

Some fixes to run the Z->mumu alignment validation on 72X and SLC6 machines
@davidlange6 @diguida @scasasso 
The gcc setup can be probably discarded (I suspect comes from  `MuonAnalysis` calibration code)
As far as I can understand from @scasasso ROOT from ```cvmfs```, i.e. in this case:
`cvmfs/cms.cern.ch/slc6_amd64_gcc481/cms/cmssw/CMSSW_7_2_1/external/slc6_amd64_gcc481/bin/root`
does not provide RooFit while ROOT from `lcg` does. 
Please correct me if I misunderstood.