CONFIG_PREFIX hack (r17670) no longer needed

package/busybox/busybox.mk

@@ -132,7 +132,7 @@ $(TARGET_DIR)/bin/busybox: $(BUSYBOX_DIR)/busybox
 ifeq ($(BR2_PACKAGE_BUSYBOX_INSTALL_SYMLINKS),y)
 	$(MAKE) CC=$(TARGET_CC) CROSS_COMPILE="$(TARGET_CROSS)" \
 		CROSS="$(TARGET_CROSS)" PREFIX="$(TARGET_DIR)" \
-		CONFIG_PREFIX="$(TARGET_DIR)" ARCH=$(KERNEL_ARCH) \
+		ARCH=$(KERNEL_ARCH) \
 		EXTRA_CFLAGS="$(TARGET_CFLAGS)" -C $(BUSYBOX_DIR) install
 else
 	install -D -m 0755 $(BUSYBOX_DIR)/busybox $(TARGET_DIR)/bin/busybox