Cannot yet use SMatrixNoInit in ROOT 6

The class SMatrixNoInit was added to ROOT in a CMS specific patch.  Unfortunately, for reasons not yet investigated, the patch is not compatible with ROOT 6, so it is not present in ROOT 6.  Therefore, for the time being, CMSSW code must use class SMatrixIdentity instead of SMatrixNoInit.
This pull request removes the remaining two compilation errors in the latest CMSSW build in the ROOT6 branch.
Please merge as soon as convenient.