rtkit: Add patch to fix format string errors

During the last staging merge I assume that we turned on
-Werror=format-security by default (haven't checked in-depth though),
which actually is a good thing.

This causes the rtkit build to now fail, so I took a patch from Debian
to fix these issues.

Signed-off-by: aszlig <aszlig@nix.build>

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

@@ -24,6 +24,12 @@ stdenv.mkDerivation rec {
       url = "http://git.0pointer.net/rtkit.git/patch/?id=88d4082ef6caf6b071d749dca1c50e7edde914cc";
       sha256 = "0hp1blbi359qz8fmr6nj4w9yc0jf3dd176f8pn25wdj38n13qkix";
     })
+
+    # Fix format string errors due to -Werror=format-security
+    (fetchpatch {
+      url = "https://sources.debian.org/data/main/r/rtkit/0.11-6/debian/patches/0006-fix-format-strings.patch";
+      sha256 = "09mr89lh16jvz6cqw00zmh0xk919bjfhjkvna1czwmafwy9p7kgp";
+    })
   ];
 
   nativeBuildInputs = [ pkgconfig ];