build: remove -fstack-protector

build: remove -fstack-protector

If gcc is built without libssp support, it loudly fails linking due to
missing __stack_chk_*() helpers. Unfortunately, gcc isn't smart enough to
disable it automatically.

systemd recently got a CC_CHECK_FLAG_APPEND helper to work around such
issues:
  http://cgit.freedesktop.org/systemd/systemd/tree/m4/attributes.m4

I didn't want to add it now, so let's just drop -fstack-protector. If we
want it, we can try adding it later again.

This partially reverts:
  commit 43752ec17d09b132621a86f5cbc546ca6ab9e977
  Author: David Herrmann <dh.herrmann@gmail.com>
  Date:   Sun Sep 1 17:45:04 2013 +0200

      Add some gcc/ld optimizations and magic

All other gcc/ld options are kept.

Reported-by: Giovanni Campagna <gcampagn@redhat.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>