gnu: mpc123: Use 'modify-phases'.

* gnu/packages/mp3.scm (mpc123)[arguments]: Use 'modify-phases'.

gnu/packages/mp3.scm

@@ -428,22 +428,20 @@ (define-public mpc123
               (patches (search-patches "mpc123-initialize-ao.patch"))))
     (build-system gnu-build-system)
     (arguments
-     '(#:phases (alist-replace
-                 'configure
+     '(#:phases
+       (modify-phases %standard-phases
+         (replace 'configure
            (lambda _
              (substitute* "Makefile"
                (("CC[[:blank:]]*:=.*")
-                      "CC := gcc\n")))
-                 (alist-replace
-                  'install
+                "CC := gcc\n"))))
+         (replace 'install
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((out (assoc-ref outputs "out"))
                     (bin (string-append out "/bin")))
                (mkdir-p bin)
-                      (install-file "mpc123" bin)))
-                  %standard-phases))
+               (install-file "mpc123" bin)))))
        #:tests? #f))
-
     (native-inputs
      `(("gettext" ,gnu-gettext)))
     (inputs