all-packages.nix: cosmetic changes

pkgs/top-level/all-packages.nix

···
 
   gperftools = callPackage ../development/libraries/gperftools { };
 
-  gst_all_1 = recurseIntoAttrs(callPackage ../development/libraries/gstreamer { 
+  gst_all_1 = recurseIntoAttrs(callPackage ../development/libraries/gstreamer {
     callPackage = pkgs.newScope (pkgs // { libav = pkgs.libav_9; });
   });