Less chatter for ’make info/dir’

* Makefile.in (${srcdir}/info/dir): Tweak shell command so
that an ordinary make says just "GEN info/dir" rather than
also having a seemingly-unrelated mv line.

Makefile.in

@@ -991,8 +991,7 @@ ${srcdir}/info/dir: ${info_dir_deps}
 	$(AM_V_at)${MKDIR_P} ${srcdir}/info
 	$(AM_V_GEN)(cd ${srcdir}/doc && \
 	 AWK='${AWK}' ../build-aux/make-info-dir ${info_dir_inputs} \
-	) >$@.tmp
-	mv $@.tmp $@
+	) >$@.tmp && mv $@.tmp $@
 
 INSTALL_DVI = install-emacs-dvi install-lispref-dvi \
 	install-lispintro-dvi install-misc-dvi