Do not use -Wp to disable fortify (BZ 31928)

Do not use -Wp to disable fortify (BZ 31928)

The -Wp does not work properly if the compiler is configured to enable
fortify by default, since it bypasses the compiler driver (which defines
the fortify flags in this case).

This patch is similar to the one used on Ubuntu [1].

I checked with a build for x86_64-linux-gnu, i686-linux-gnu,
aarch64-linux-gnu, s390x-linux-gnu, and riscv64-linux-gnu with
gcc-13 that enables the fortify by default.

Co-authored-by: Matthias Klose <matthias.klose@canonical.com>
[1] https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/glibc/tree/debian/patches/ubuntu/fix-fortify-source.patch
Reviewed-by: DJ Delorie <dj@redhat.com>