inversepath/usbarmory: fix evaluation

inversepath/usbarmory/kernel.nix

@@ -0,0 +1,20 @@
+{ stdenv, buildLinux, fetchurl }:
+
+buildLinux {
+  inherit stdenv;
+  version = "4.4.0";
+
+  src = fetchurl {
+    url = "mirror://kernel/linux/kernel/v4.x/linux-4.4.tar.xz";
+    sha256 = "401d7c8fef594999a460d10c72c5a94e9c2e1022f16795ec51746b0d165418b2";
+  };
+
+  configfile = ./kernel.config;
+
+  kernelPatches = [{
+    patch = ./usbarmory-dts.patch;
+    name = "usbarmory-dts";
+  }];
+
+  allowImportFromDerivation = true;
+}