Revert "Merge branch 'modprobe-fix' of git://github.com/abbradar/nixpkgs"

Was meant to go into staging, sorry

This reverts commit 57b2d1e9b0, reversing
changes made to 760b2b9048.

nixos/modules/services/hardware/udev.nix

@@ -58,7 +58,7 @@ let
       # Fix some paths in the standard udev rules.  Hacky.
       for i in $out/*.rules; do
         substituteInPlace $i \
-          --replace \"/sbin/modprobe \"${pkgs.kmod}/bin/modprobe \
+          --replace \"/sbin/modprobe \"${config.system.sbin.modprobe}/sbin/modprobe \
           --replace \"/sbin/mdadm \"${pkgs.mdadm}/sbin/mdadm \
           --replace \"/sbin/blkid \"${pkgs.utillinux}/sbin/blkid \
           --replace \"/bin/mount \"${pkgs.utillinux}/bin/mount \
@@ -316,7 +316,8 @@ in
       '';
 
     systemd.services.systemd-udevd =
-      { restartTriggers = cfg.packages;
+      { environment.MODULE_DIR = "/run/booted-system/kernel-modules/lib/modules";
+        restartTriggers = cfg.packages;
       };
 
   };