busybox: rebuild if .config changed

As reported on irc - Fixes busybox-menuconfig

package/busybox/busybox.mk

@@ -42,7 +42,7 @@ else
 endif
 	touch $@
 
-$(BUSYBOX_DIR)/.configured: $(BUSYBOX_DIR)/.unpacked $(BUSYBOX_CONFIG_FILE)
+$(BUSYBOX_DIR)/.config: $(BUSYBOX_DIR)/.unpacked $(BUSYBOX_CONFIG_FILE)
 	cp -f $(BUSYBOX_CONFIG_FILE) $(BUSYBOX_DIR)/.config
 	$(SED) s,^CONFIG_PREFIX=.*,CONFIG_PREFIX=\"$(TARGET_DIR)\", \
 		$(BUSYBOX_DIR)/.config
@@ -97,7 +97,7 @@ endif
 	touch $@
 
 
-$(BUSYBOX_DIR)/busybox: $(BUSYBOX_DIR)/.configured
+$(BUSYBOX_DIR)/busybox: $(BUSYBOX_DIR)/.config
 	$(MAKE) CC=$(TARGET_CC) CROSS_COMPILE="$(TARGET_CROSS)" \
 		CROSS="$(TARGET_CROSS)" PREFIX="$(TARGET_DIR)" \
 		ARCH=$(KERNEL_ARCH) \
@@ -129,9 +129,9 @@ busybox-source: $(DL_DIR)/$(BUSYBOX_SOURCE)
 
 busybox-unpacked: host-sed $(PROJECT_BUILD_DIR) $(BUSYBOX_DIR)/.unpacked
 
-busybox-config: host-sed $(PROJECT_BUILD_DIR) $(BUSYBOX_DIR)/.configured
+busybox-config: host-sed $(PROJECT_BUILD_DIR) $(BUSYBOX_DIR)/.config
 
-busybox-menuconfig: host-sed $(PROJECT_BUILD_DIR) busybox-source $(BUSYBOX_DIR)/.configured
+busybox-menuconfig: host-sed $(PROJECT_BUILD_DIR) busybox-source $(BUSYBOX_DIR)/.config
 	$(MAKE) __TARGET_ARCH=$(ARCH) -C $(BUSYBOX_DIR) menuconfig
 
 busybox-update: