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/os-specific/linux/libtracefs/default.nix

@@ -0,0 +1,51 @@
+{ lib
+, stdenv
+, fetchgit
+, pkg-config
+, libtraceevent
+, asciidoc
+, xmlto
+, docbook_xml_dtd_45
+, docbook_xsl
+, coreutils
+, which
+, valgrind
+, sourceHighlight
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libtracefs";
+  version = "1.3.0";
+
+  src = fetchgit {
+    url = "git://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git";
+    rev = "libtracefs-${version}";
+    sha256 = "sha256-Kg1mPjTZ2UCeco18Fa8GqmLo2R35XvUE/q2J1HAmtEc=";
+  };
+
+  postPatch = ''
+    substituteInPlace scripts/utils.mk --replace /bin/pwd ${coreutils}/bin/pwd
+    patchShebangs check-manpages.sh
+  '';
+
+  outputs = [ "out" "dev" "devman" "doc" ];
+  enableParallelBuilding = true;
+  nativeBuildInputs = [ pkg-config asciidoc xmlto docbook_xml_dtd_45 docbook_xsl which valgrind sourceHighlight ];
+  buildInputs = [ libtraceevent ];
+  makeFlags = [
+    "prefix=${placeholder "out"}"
+    "doc"                       # build docs
+  ];
+  installFlags = [
+    "pkgconfig_dir=${placeholder "out"}/lib/pkgconfig"
+    "install_doc"
+  ];
+
+  meta = with lib; {
+    description = "Linux kernel trace file system library";
+    homepage    = "https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/";
+    license     = licenses.lgpl21Only;
+    platforms   = platforms.linux;
+    maintainers = with maintainers; [ wentasah ];
+  };
+}