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>

pkgs/build-support/rust/fetchcrate.nix

@@ -0,0 +1,38 @@
+{ lib, fetchurl, unzip }:
+
+{ crateName ? args.pname
+, pname ? null
+, version
+, sha256
+, ... } @ args:
+
+assert pname == null || pname == crateName;
+
+lib.overrideDerivation (fetchurl ({
+
+  name = "${crateName}-${version}.tar.gz";
+  url = "https://crates.io/api/v1/crates/${crateName}/${version}/download";
+  recursiveHash = true;
+
+  downloadToTemp = true;
+
+  postFetch =
+    ''
+      export PATH=${unzip}/bin:$PATH
+
+      unpackDir="$TMPDIR/unpack"
+      mkdir "$unpackDir"
+      cd "$unpackDir"
+
+      renamed="$TMPDIR/${crateName}-${version}.tar.gz"
+      mv "$downloadedFile" "$renamed"
+      unpackFile "$renamed"
+      fn=$(cd "$unpackDir" && echo *)
+      if [ -f "$unpackDir/$fn" ]; then
+        mkdir $out
+      fi
+      mv "$unpackDir/$fn" "$out"
+    '';
+} // removeAttrs args [ "crateName" "pname" "version" ]))
+# Hackety-hack: we actually need unzip hooks, too
+(x: {nativeBuildInputs = x.nativeBuildInputs++ [unzip];})