slstatus: fix cross-compilation

+2
+2
pkgs/applications/misc/slstatus/default.nix
··· 20 20 nativeBuildInputs = [ pkg-config ]; 21 21 buildInputs = [ libX11 ]; 22 22 23 + makeFlags = [ "CC:=$(CC)" ]; 24 + 23 25 installFlags = [ "PREFIX=$(out)" ]; 24 26 25 27 meta = {