gnu: samtools: Use "modify-phases" syntax.

* gnu/packages/bioinformatics.scm (samtools)[arguments]: Use "modify-phases"
syntax.

gnu/packages/bioinformatics.scm

@@ -4533,29 +4533,26 @@ to the user's query of interest.")
        #:make-flags (list (string-append "prefix=" (assoc-ref %outputs "out")))
        #:configure-flags (list "--with-ncurses")
        #:phases
-       (alist-cons-after
-        'unpack 'patch-tests
+       (modify-phases %standard-phases
+         (add-after 'unpack 'patch-tests
            (lambda _
              (substitute* "test/test.pl"
                ;; The test script calls out to /bin/bash
                (("/bin/bash") (which "bash")))
-          #t)
-        (alist-cons-after
-         'install 'install-library
+             #t))
+         (add-after 'install 'install-library
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((lib (string-append (assoc-ref outputs "out") "/lib")))
                (install-file "libbam.a" lib)
-             #t))
-         (alist-cons-after
-          'install 'install-headers
+               #t)))
+         (add-after 'install 'install-headers
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((include (string-append (assoc-ref outputs "out")
                                            "/include/samtools/")))
                (for-each (lambda (file)
                            (install-file file include))
                          (scandir "." (lambda (name) (string-match "\\.h$" name))))
-              #t))
-          %standard-phases)))))
+               #t))))))
     (native-inputs `(("pkg-config" ,pkg-config)))
     (inputs `(("ncurses" ,ncurses)
               ("perl" ,perl)