Changed textual representation of a goal.

git-svn-id: https://svn.sosy-lab.org/software/cpachecker/branches/tiger2checker@13076 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c
merge with tiger2checker


git-svn-id: https://svn.sosy-lab.org/software/cpachecker/branches/cpatiger-variabilityAware@13079 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c