Clean up the vsftpd module a bit

pkgs/servers/ftp/vsftpd/default.nix

@@ -1,23 +1,29 @@
 { stdenv, fetchurl, openssl, sslEnable ? false, libcap, pam }:
 
-stdenv.mkDerivation (rec {
+stdenv.mkDerivation rec {
   name = "vsftpd-3.0.2";
-  
+
   src = fetchurl {
     url = "https://security.appspot.com/downloads/${name}.tar.gz";
     sha256 = "0mjy345wszskz1vnk83360c1y37arwgap3gwz8hy13sjqpig0imy";
   };
 
+  preConfigure = stdenv.lib.optionalString sslEnable ''
+    echo "Will enable SSL"
+    sed -i "/VSF_BUILD_SSL/s/^#undef/#define/" builddefs.h
+  '';
+
   # The gcc-wrappers use -idirafter for glibc, and vsftpd also, and
   # their dummyinc come before those of glibc, then the build works bad.
   prePatch = ''
     sed -i -e 's/-idirafter.*//' Makefile
   '';
-  
-  preBuild = let
-      sslLibs = if sslEnable then "-lcrypt -lssl -lcrypto " else "";
+
+  preBuild =
+    let
+      sslLibs = if sslEnable then "-lcrypt -lssl -lcrypto" else "";
     in ''
-      makeFlagsArray=( "LIBS=${sslLibs}-lpam -lcap -fstack-protector" )
+      makeFlagsArray=( "LIBS=${sslLibs} -lpam -lcap -fstack-protector" )
     '';
 
   # It won't link without this flag, used in CFLAGS
@@ -35,11 +41,4 @@ stdenv.mkDerivation (rec {
     mkdir -pv $out/etc/xinetd.d
     install -v -m 644 xinetd.d/vsftpd $out/etc/xinetd.d/vsftpd
   '';
-} // (if sslEnable then {
-  preConfigure = ''
-    echo "Will enable SSL"
-    sed -i "/VSF_BUILD_SSL/s/^#undef/#define/" builddefs.h
-  '';
-
-} else { })
-)
+}