Make gbuild-to-ide more pep8 compliant

Minor style cleanup
Remove unused variables

Change-Id: Id4c190f24f51dfc676c268dac1c19e3f03d3988d
Reviewed-on: https://gerrit.libreoffice.org/11633
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>