FortranCInterface: Fix PathScale detection again
PathScale Fortran mangles module symbols as "MY_SUB.in.MY_MODULE" and also requires "my_module_" when the module is imported. We cannot provide the symbol with ".in." mangling so we should not provide "my_module_" because it would duplicate the one in the Fortran-provided object file. Commit "FortranCInterface: Fix PathScale detection" (2010-01-22) already made the same fix for the non-underscore module case.