gnu: kmod: Update phase style.

* gnu/packages/linux.scm (kmod)[arguments]: Use MODIFY-PHASES syntax and
end phase in #t.

gnu/packages/linux.scm

@@ -1952,8 +1952,9 @@ to use Linux' inotify mechanism, which allows file accesses to be monitored.")
     (arguments
      `(#:tests? #f                      ; FIXME: Investigate test failures
        #:configure-flags '("--with-xz" "--with-zlib")
-       #:phases (alist-cons-after
-                 'install 'install-modprobe&co
+       #:phases
+       (modify-phases %standard-phases
+         (add-after 'install 'install-modprobe&co
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((out (assoc-ref outputs "out"))
                     (bin (string-append out "/bin")))
@@ -1961,8 +1962,8 @@ to use Linux' inotify mechanism, which allows file accesses to be monitored.")
                            (symlink "kmod"
                                     (string-append bin "/" tool)))
                          '("insmod" "rmmod" "lsmod" "modprobe"
-                                 "modinfo" "depmod"))))
-                 %standard-phases)))
+                           "modinfo" "depmod"))
+               #t))))))
     (home-page "https://www.kernel.org/")
     (synopsis "Kernel module tools")
     (description "Kmod is a set of tools to handle common tasks with Linux