Makefile: do not link rev-list any specially.

We used to depend on bignum from openssl for rev-list to compute
merge-order, but there is no reason to use different build
recipe from other programs anymore.  Just build it with git-%$X
rule like everybody else.

Noticed by Alexey Dobriyan.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Makefile

@@ -564,10 +564,6 @@ git-http-push$X: revision.o http.o http-push.o $(LIB_FILE)
 	$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
-git-rev-list$X: rev-list.o $(LIB_FILE)
-	$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
-		$(LIBS) $(OPENSSL_LIBSSL)
-
 init-db.o: init-db.c
 	$(CC) -c $(ALL_CFLAGS) \
 		-DDEFAULT_GIT_TEMPLATE_DIR='"$(template_dir_SQ)"' $*.c