[Bug target/91148] PowerPC build gets several warnings due to -Wformat-diag

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91148

--- Comment #10 from Segher Boessenkool <segher at gcc dot gnu.org> ---
And yes, that means a lot of work for whoever wants to make the warning
default (during GCC builds or otherwise).

The alternative is a lot of work for other people.  That is not a good
alternative.