tree-wide: fix all revs of fetchsvn

pkgs/misc/cups/drivers/splix/default.nix

@@ -1,7 +1,6 @@
 { stdenv, fetchsvn, fetchurl, cups, cups-filters, jbigkit, zlib }:
 
 let
-  rev = "315";
 
   color-profiles = stdenv.mkDerivation {
     name = "splix-color-profiles-20070625";
@@ -19,14 +18,15 @@ let
     '';
   };
 
-in stdenv.mkDerivation {
+in stdenv.mkDerivation rec {
   name = "splix-svn-${rev}";
+  rev = "315";
 
   src = fetchsvn {
     # We build this from svn, because splix hasn't been in released in several years
     # although the community has been adding some new printer models.
     url = "svn://svn.code.sf.net/p/splix/code/splix";
-    rev = "r${rev}";
+    inherit rev;
     sha256 = "16wbm4xnz35ca3mw2iggf5f4jaxpyna718ia190ka6y4ah932jxl";
   };