Revert "build: enable LTO and _FORTIFY_SOURCE with optimization"
Revert "build: enable LTO and _FORTIFY_SOURCE with optimization"

This reverts commit 27bcc9111b63e94d091c3fa47e81fe52b806cd3e.

Let the distro decide about this flag. It's relatively recent and
doesn't work well with gcc 4.[678] making the testsuite to fail.

pmmccorm/kmod,lpereira/kmod,lucasdemarchi/kmod,Distrotech/kmod,pmmccorm/kmod,pmmccorm/kmod,lpereira/kmod,Distrotech/kmod,lpereira/kmod,lucasdemarchi/kmod,Distrotech/kmod,lucasdemarchi/kmod