Fix some warnings and compile errors generated by the new
fortify-headers when compiling some applications like strace.
Fixes: 6268692bd2 ("toolchain: fortify-headers: Update to version 2.3.3")
Link: https://github.com/openwrt/openwrt/pull/20561
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
