procmail: minor cleanup

pkgs/applications/misc/procmail/default.nix

@@ -4,6 +4,11 @@ stdenv.mkDerivation rec {
   pname = "procmail";
   version = "3.22";
 
+  src = fetchurl {
+    url = "ftp://ftp.fu-berlin.de/pub/unix/mail/procmail/procmail-${version}.tar.gz";
+    sha256 = "05z1c803n5cppkcq99vkyd5myff904lf9sdgynfqngfk9nrpaz08";
+  };
+
   patches = [
     ./CVE-2014-3618.patch
     (fetchurl {
@@ -16,20 +21,16 @@ stdenv.mkDerivation rec {
   # getline is defined differently in glibc now. So rename it.
   # Without the .PHONY target "make install" won't install anything on Darwin.
   postPatch = ''
-        sed -e "s%^RM.*$%#%" -i Makefile
-        sed -e "s%^BASENAME.*%\BASENAME=$out%" -i Makefile
-        sed -e "s%^LIBS=.*%LIBS=-lm%" -i Makefile
-        sed -e "s%getline%thisgetline%g" -i src/*.c src/*.h
-        sed -e "3i\
+    sed -i Makefile \
+      -e "s%^RM.*$%#%" \
+      -e "s%^BASENAME.*%\BASENAME=$out%" \
+      -e "s%^LIBS=.*%LIBS=-lm%"
+    sed -e "s%getline%thisgetline%g" -i src/*.c src/*.h
+    sed -e "3i\
     .PHONY: install
     " -i Makefile
   '';
 
-  src = fetchurl {
-    url = "ftp://ftp.fu-berlin.de/pub/unix/mail/procmail/procmail-${version}.tar.gz";
-    sha256 = "05z1c803n5cppkcq99vkyd5myff904lf9sdgynfqngfk9nrpaz08";
-  };
-
   meta = with lib; {
     description = "Mail processing and filtering utility";
     homepage = "http://www.procmail.org/";