gnu: multitail: Remove bogus use of DESTDIR.

* gnu/packages/logging.scm (multitail)[arguments]: Use the PREFIX
variable instead.

gnu/packages/logging.scm

@@ -3,7 +3,7 @@
 ;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2017 Stefan Reichör <stefan@xsteve.at>
 ;;; Copyright © 2017 Eric Bavier <bavier@member.fsf.org>
-;;; Copyright © 2018, 2019 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2018, 2019, 2020 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2019 Gábor Boskovits <boskovits@gmail.com>
 ;;; Copyright © 2019 Meiyo Peng <meiyo@riseup.net>
 ;;; Copyright © 2020 Marius Bakke <mbakke@fastmail.com>
@@ -166,8 +166,7 @@ (define-public multitail
     (arguments
      `(#:make-flags
        (list "CC=gcc"
-             "PREFIX="
-             (string-append "DESTDIR="
+             (string-append "PREFIX="
                             (assoc-ref %outputs "out")))
        #:phases
        (modify-phases %standard-phases