fix dependancy

package/busybox/busybox.mk

@@ -25,7 +25,7 @@ $(DL_DIR)/$(BUSYBOX_SOURCE):
 
 busybox-source: $(DL_DIR)/$(BUSYBOX_SOURCE) $(BUSYBOX_CONFIG_FILE)
 
-$(BUSYBOX_DIR)/.unpacked: $(DL_DIR)/$(BUSYBOX_SOURCE) $(BUILD_DIR)
+$(BUSYBOX_DIR)/.unpacked: $(DL_DIR)/$(BUSYBOX_SOURCE)
 	$(BUSYBOX_UNZIP) $(DL_DIR)/$(BUSYBOX_SOURCE) | tar -C $(BUILD_DIR) $(TAR_OPTIONS) -
 ifeq ($(BR2_PACKAGE_SYSKLOGD),y)
 	# if we have external syslogd, force busybox to use it