Don't overwrite /bin/busybox with patch

make/patch.mk

@@ -44,6 +44,7 @@ $(GNUPATCH_DIR)/$(GNUPATCH_BINARY): $(GNUPATCH_DIR)/.configured
 	$(MAKE) CC=$(TARGET_CC) -C $(GNUPATCH_DIR)
 
 $(TARGET_DIR)/$(GNUPATCH_TARGET_BINARY): $(GNUPATCH_DIR)/$(GNUPATCH_BINARY)
+	rm -f $(TARGET_DIR)/$(GNUPATCH_TARGET_BINARY)
 	cp -a $(GNUPATCH_DIR)/$(GNUPATCH_BINARY) $(TARGET_DIR)/$(GNUPATCH_TARGET_BINARY)
 
 patch: uclibc $(TARGET_DIR)/$(GNUPATCH_TARGET_BINARY)