Makefile: .o already depends on its .h file

We can remove the explicit depend on the .h file because that is covered
by depends.mk. Let's instead depend on makeflags which makes more sense.

Signed-off-by: Kai Krakow <kai@kaishome.de>

lib/Makefile

@@ -31,7 +31,7 @@ depends.mk: *.cc
 
 include depends.mk
 
-%.o: %.cc ../include/crucible/%.h
+%.o: %.cc ../makeflags
 	$(CXX) $(CXXFLAGS) -fPIC -o $@ -c $<
 
 libcrucible.so: $(OBJS) Makefile