pkgs/cfs-zen-tweaks: fix exec permission

pkgs/os-specific/linux/cfs-zen-tweaks/default.nix

@@ -17,21 +17,16 @@ stdenv.mkDerivation rec {
     sha256 = "HRR2tdjNmWyrpbcMlihSdb/7g/tHma3YyXogQpRCVyo=";
   };
 
-  postPatch = ''
-    patchShebangs set-cfs-zen-tweaks.bash
-    chmod +x set-cfs-zen-tweaks.bash
+  preConfigure = ''
     substituteInPlace set-cfs-zen-tweaks.bash \
       --replace '$(gawk' '$(${gawk}/bin/gawk'
   '';
 
-  buildInputs = [
-    gawk
-  ];
+  preFixup = ''
+    chmod +x $out/lib/cfs-zen-tweaks/set-cfs-zen-tweaks.bash
+  '';
 
-  nativeBuildInputs = [
-    cmake
-    makeWrapper
-  ];
+  nativeBuildInputs = [ cmake ];
 
   meta = with lib; {
     description = "Tweak Linux CPU scheduler for desktop responsiveness";