pflask: pull fix pending upstream inclusion for -fno-common support
pflask: pull fix pending upstream inclusion for -fno-common support

Without the change build fails on upstream gcc-10 as:

    ld: src/util.c.1.o:/build/pflask/build/../src/printf.h:42: multiple definition of
      `use_syslog'; src/cgroup.c.1.o:/build/pflask/build/../src/printf.h:42: first defined here

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs