Add * to a few printed string pointers and fix builds/tests.
Add * to a few printed string pointers and fix builds/tests.

Found by `go vet` in https://travis-ci.org/chromium/hstspreload/jobs/124899185

chromium/hstspreload.org,chromium/hstspreload.org,chromium/hstspreload.org,chromium/hstspreload.org