(lisp, shortlisp): Use cus-start.elc, not cus-start.el.

src/Makefile.in

@@ -647,7 +647,7 @@ lisp= \
 	${lispsource}buff-menu.elc \
 	${lispsource}button.elc \
 	${lispsource}byte-run.elc \
-	${lispsource}cus-start.el \
+	${lispsource}cus-start.elc \
 	${lispsource}custom.elc \
 	${lispsource}emacs-lisp/lisp-mode.elc \
 	${lispsource}emacs-lisp/lisp.elc \
@@ -730,7 +730,7 @@ shortlisp= \
 	../lisp/buff-menu.elc \
 	../lisp/button.elc \
 	../lisp/byte-run.elc \
-	../lisp/cus-start.el \
+	../lisp/cus-start.elc \
 	../lisp/custom.elc \
 	../lisp/emacs-lisp/backquote.elc \
 	../lisp/emacs-lisp/lisp-mode.elc \