Remove uses of mkFixStrictness

mkFixStrictness is no longer needed, woohoo!

lib/options.nix

@@ -6,6 +6,7 @@ with import ./trivial.nix;
 with import ./lists.nix;
 with import ./misc.nix;
 with import ./attrsets.nix;
+with import ./strings.nix;
 
 rec {
 

nixos/modules/services/x11/display-managers/kdm.nix

@@ -128,7 +128,7 @@ in
     services.xserver.displayManager.slim.enable = false;
 
     services.xserver.displayManager.job =
-      { execCmd = mkFixStrictness
+      { execCmd =
           ''
             mkdir -m 0755 -p /var/lib/kdm
             chown kdm /var/lib/kdm

nixos/modules/services/x11/display-managers/lightdm.nix

@@ -96,7 +96,7 @@ in
       logsXsession = true;
 
       # lightdm relaunches itself via just `lightdm`, so needs to be on the PATH
-      execCmd = mkFixStrictness ''
+      execCmd = ''
         export PATH=${lightdm}/sbin:$PATH
         ${lightdm}/sbin/lightdm --log-dir=/var/log --run-dir=/run --config=${lightdmConf}
       '';

nixos/modules/system/boot/loader/grub/memtest.nix

@@ -23,7 +23,7 @@ in
 
   config = mkIf config.boot.loader.grub.memtest86 {
 
-    boot.loader.grub.extraEntries = mkFixStrictness (
+    boot.loader.grub.extraEntries =
       if config.boot.loader.grub.version == 2 then
         ''
           menuentry "Memtest86+" {
@@ -31,7 +31,7 @@ in
           }
         ''
       else
-        throw "Memtest86+ is not supported with GRUB 1.");
+        throw "Memtest86+ is not supported with GRUB 1.";
 
     boot.loader.grub.extraFiles."memtest.bin" = "${memtest86}/memtest.bin";