make: fix generation of .d files

Makefile

@@ -1,21 +1,19 @@
 TARGET = Log.o
 TEST   = test
 LOG_USEMUTEX ?= 0
-CFLAGS = -O2 -std=c++11 -Wall -Wextra -pedantic-errors -g -DLOG_USEMUTEX=$(LOG_USEMUTEX)
+CXXFLAGS = -O2 -g -std=c++11 -Wall -Wextra -pedantic-errors -MMD -DLOG_USEMUTEX=$(LOG_USEMUTEX)
 
 .PHONY: all clean
 
 all: $(TARGET)
 
-test: $(TARGET) $(TEST).o
-	$(CXX) -o test $^
+$(TEST): $(TARGET) $(TEST).o
+	$(CXX) -o $(TEST) $^
 
 %.o: %.cpp
-	$(CXX) $(INCLUDES) $^ -MM -MT $@ > $*.d
-	$(CXX) -c -o $@ $(CFLAGS) $^
+	$(CXX) -c -o $@ $(CXXFLAGS) $<
 
 clean:
 	$(RM) $(TARGET) $(TEST) *.d *.o *.log
 
 -include *.d
-