gnu: libkomparediff2: Fix source file name.

* gnu/packages/kde.scm (libkomparediff2)[source]: Remove (incorrect)
FILE-NAME.

gnu/packages/kde.scm

@@ -2,7 +2,7 @@
 ;;; Copyright © 2016, 2017, 2019 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2016, 2017 Thomas Danckaert <post@thomasdanckaert.be>
 ;;; Copyright © 2017, 2018 Mark Meyer <mark@ofosos.org>
-;;; Copyright © 2017, 2018 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2017, 2018, 2019 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2018 Gábor Boskovits <boskovits@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -456,7 +456,6 @@ (define-public libkomparediff2
         (method url-fetch)
         (uri (string-append "mirror://kde/stable/applications"
                             "/" version "/src/" name "-" version ".tar.xz"))
-        (file-name (string-append name "-" version ".tar.gz"))
         (sha256
          (base32
           "0w6p8lvm2rn7y4qz0x3s87lwh1758xnyhwkkkng55n8v9rpjjw7l"))))