uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/tasks/filesystems/ext.nix

@@ -0,0 +1,28 @@
+{ config, lib, pkgs, ... }:
+
+let
+
+  inInitrd = lib.any (fs: fs == "ext2" || fs == "ext3" || fs == "ext4") config.boot.initrd.supportedFilesystems;
+
+in
+
+{
+  config = {
+
+    system.fsPackages = lib.mkIf (config.boot.initrd.systemd.enable -> inInitrd) [ pkgs.e2fsprogs ];
+
+    # As of kernel 4.3, there is no separate ext3 driver (they're also handled by ext4.ko)
+    boot.initrd.availableKernelModules = lib.mkIf (config.boot.initrd.systemd.enable -> inInitrd) [ "ext2" "ext4" ];
+
+    boot.initrd.extraUtilsCommands = lib.mkIf (!config.boot.initrd.systemd.enable)
+      ''
+        # Copy e2fsck and friends.
+        copy_bin_and_libs ${pkgs.e2fsprogs}/sbin/e2fsck
+        copy_bin_and_libs ${pkgs.e2fsprogs}/sbin/tune2fs
+        ln -sv e2fsck $out/bin/fsck.ext2
+        ln -sv e2fsck $out/bin/fsck.ext3
+        ln -sv e2fsck $out/bin/fsck.ext4
+      '';
+
+  };
+}