internal/logger: fix exported functions comments
internal/logger: fix exported functions comments

It's expected that the comments for exported functions start with the
exact function name, which wasn't for both Fatalf and Fatalln, as
reported by golint.

Signed-off-by: Bruno Meneguele <82c7731bc2625bcbab88bc571aee6631ba3f66f3@redhat.com>

zaquestion/lab,zaquestion/lab