exp/cmd/godef: fix StructType case
exp/cmd/godef: fix StructType case

rogpeppe/godef,ManojkumarV/godef,cmars/tools,abourget/godef,cmars/tools,cmars/tools,gonotes/godef,tw4452852/godef,pepin/godef,lukehoban/godef,cmars/tools,grafov/godef