bbswitch: upgrade to 0.5 - add linux 3.8 compatibility patch

pkgs/os-specific/linux/bbswitch/default.nix

@@ -1,9 +1,14 @@
 { stdenv, fetchurl, kernel }:
 
 let
-  baseName = "bbswitch-0.4.2";
+  baseName = "bbswitch-0.5";
   name = "${baseName}-${kernel.version}";
 
+  linux38Compatibility = fetchurl {
+    url = "http://github.com/Bumblebee-Project/bbswitch/commit/5593d95.patch";
+    sha256 = "0m6y5sdagf4brhk1lsp86rx94xf628sixzf6j71bn7jnqs4jslr6";
+  };
+
 in
 
 stdenv.mkDerivation {
@@ -11,15 +16,17 @@ stdenv.mkDerivation {
 
   src = fetchurl {
     url = "http://github.com/downloads/Bumblebee-Project/bbswitch/${baseName}.tar.gz";
-    sha256 = "06j3cm1rk3lcbv54k0magrijykrzmkrna8n5cc274iz59842lga3";
+    sha256 = "19775r3bsf5l3ssbayr30fij09gavj2qjrr438hdcmzswvlj2dpv";
   };
 
+  patches = [ linux38Compatibility ];
+
   preBuild = ''
     substituteInPlace Makefile \
       --replace "\$(shell uname -r)" "${kernel.modDirVersion}" \
       --replace "/lib/modules" "${kernel}/lib/modules"
   '';
- 
+
   installPhase = ''
     ensureDir $out/lib/modules/${kernel.modDirVersion}/misc
     cp bbswitch.ko $out/lib/modules/${kernel.modDirVersion}/misc