If the compiler can detect an issue with a format string at compile
time, then we should take advantage of that and turn the issue into a
hard compile-time error as such problems almost always lead to UB.
This helps with catching logging or assertion messages that have been
converted over to fmt but are still using the old, non-fmt variants
of the logging macros.
This commit also fixes all incorrect usages that I could find.
Léo Lam