port back patch introduced shortly after the 4.0.5 release. Fixes: checking for __NR_pidfd_open... no configure: error: Neither pidfd_open or __NR_pidfd_open found. Disable pidwait with configure option --disable-pidwait happening with this defconfig: BR2_arm=y BR2_cortex_a15_a7=y BR2_TOOLCHAIN_EXTERNAL=y BR2_INIT_SYSTEMD=y BR2_PACKAGE_PROCPS_NG=y Signed-off-by: Michael Nosthoff <buildroot@heine.tech> Signed-off-by: Julien Olivain <ju.o@free.fr>