subtree: make install targets depend on build targets

Now that we have build targets let the install targets depend on them.
Also make the targets phony.

Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/subtree/Makefile

@@ -69,11 +69,11 @@ install: $(GIT_SUBTREE)
 
 install-doc: install-man install-html
 
-install-man: $(GIT_SUBTREE_DOC)
+install-man: man
 	$(INSTALL) -d -m 755 $(DESTDIR)$(man1dir)
 	$(INSTALL) -m 644 $^ $(DESTDIR)$(man1dir)
 
-install-html: $(GIT_SUBTREE_HTML)
+install-html: html
 	$(INSTALL) -d -m 755 $(DESTDIR)$(htmldir)
 	$(INSTALL) -m 644 $^ $(DESTDIR)$(htmldir)
 
@@ -98,4 +98,4 @@ clean:
 	$(RM) $(GIT_SUBTREE)
 	$(RM) *.xml *.html *.1
 
-.PHONY: FORCE
+.PHONY: FORCE man html install-man install-html