Auto merge of #139632 - Darksonn:cfi-fmt, r=m-ou-se

cfi: do not transmute function pointers in formatting code

Follow-up to #115954.
Addresses #115199 point 2.
Related to #128728.
Discussion [on the LKML](https://lore.kernel.org/all/[email protected]/).

cc `@maurer` `@rcvalle` `@RalfJung`

Author: bors