gnu: infiniband-diags: Remove custom bootstrap phase.

* gnu/packages/fabric-management.scm (infiniband-diags)[arguments]: Remove
"autotools" phase.

gnu/packages/fabric-management.scm

 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2017 Dave Love <fx@gnu.org>
 ;;; Copyright © 2018 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -120,9 +121,6 @@ (define-public infiniband-diags
              "--disable-static")
        #:phases
        (modify-phases %standard-phases
-         (add-before 'configure 'autotools
-           (lambda _
-             (zero? (system "./autogen.sh"))))
          (add-after 'install 'licence
            (lambda _
              (let ((doc (string-append (assoc-ref %outputs "lib") "/share/doc")))