Issues were:
# github.com/rfjakob/gocryptfs/contrib/findholes/holes
contrib/findholes/holes/holes.go:136:2: unreachable code
# github.com/rfjakob/gocryptfs/tests/root_test_test
tests/root_test/root_test.go:139:2: unreachable code
Also make sure we actually run "go vet" against the whole
codebase.