pcsc-cyberjack: minor cleanups

pkgs/tools/security/pcsc-cyberjack/default.nix

@@ -1,25 +1,28 @@
 { stdenv, fetchurl, autoreconfHook, pkgconfig, libusb1, pcsclite }:
 
-stdenv.mkDerivation rec {
-  pname = "pcsc-cyberjack";
-  version = "3.99.5_SP13";
+let
+  version = "3.99.5";
+  suffix = "SP13";
+  tarBall = "${version}final.${suffix}";
 
-  src = with stdenv.lib; let
-    splittedVer = splitString "_" version;
-    mainVer = if length splittedVer >= 1 then head splittedVer else version;
-    spVer = optionalString (length splittedVer >= 1) ("." + last splittedVer);
-    tarballVersion = "${mainVer}final${spVer}";
-  in fetchurl {
-    url = "http://support.reiner-sct.de/downloads/LINUX/V${version}"
-        + "/pcsc-cyberjack_${tarballVersion}.tar.gz";
+in stdenv.mkDerivation rec {
+  pname = "pcsc-cyberjack";
+  inherit version;
+
+  src = fetchurl {
+    url =
+      "http://support.reiner-sct.de/downloads/LINUX/V${version}_${suffix}/${pname}_${tarBall}.tar.gz";
     sha256 = "1lx4bfz4riz7j77sl65akyxzww0ygm63w0c1b75knr1pijlv8d3b";
   };
 
   outputs = [ "out" "tools" ];
 
   nativeBuildInputs = [ autoreconfHook pkgconfig ];
+
   buildInputs = [ libusb1 pcsclite ];
 
+  enableParallelBuilding = true;
+
   configureFlags = [
     "--with-usbdropdir=${placeholder "out"}/pcsc/drivers"
     "--bindir=${placeholder "tools"}/bin"
@@ -31,7 +34,7 @@ stdenv.mkDerivation rec {
     description = "REINER SCT cyberJack USB chipcard reader user space driver";
     homepage = "https://www.reiner-sct.com/";
     license = licenses.gpl2Plus;
-    platforms = platforms.linux;
     maintainers = with maintainers; [ aszlig ];
+    platforms = platforms.linux;
   };
 }