Makefile: use $^ to avoid listing prerequisites on the command line

There's no need to list again the prerequisites.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -2043,13 +2043,13 @@ $(REMOTE_CURL_PRIMARY): remote-curl.o http.o http-walker.o GIT-LDFLAGS $(GITLIBS
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
 $(LIB_FILE): $(LIB_OBJS)
-	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS)
+	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $^
 
 $(XDIFF_LIB): $(XDIFF_OBJS)
-	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(XDIFF_OBJS)
+	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $^
 
 $(VCSSVN_LIB): $(VCSSVN_OBJS)
-	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(VCSSVN_OBJS)
+	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $^
 
 export DEFAULT_EDITOR DEFAULT_PAGER