package/libubox: fix lua module install path

The LUAPATH variable is only used when installing the lua module, and
cmake knows very well how to do out-of-tree isntalls, so there is no
reason to include the staging path in LUAPATH, which will cause our
post-install sanity checks to kick in and whine:

    libubox: installs files in /home/lhk/workspace/orangepi/host/usr/a
    rm-buildroot-linux-gnueabihf/sysroot//home/lhk/workspace/orangepi

As for libuci, just pass the runtime LUAPATH.

Fixes #9856

Reported-by: linhuikui@gmail.com
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libubox/libubox.mk

@@ -13,7 +13,7 @@ LIBUBOX_DEPENDENCIES = $(if $(BR2_PACKAGE_JSON_C),json-c)
 ifeq ($(BR2_USE_MMU)$(BR2_PACKAGE_LUA_5_1),yy)
 LIBUBOX_DEPENDENCIES += lua
 LIBUBOX_CONF_OPTS += -DBUILD_LUA=ON \
-	-DLUAPATH=$(STAGING_DIR)/usr/lib/lua/5.1 \
+	-DLUAPATH=/usr/lib/lua/5.1 \
 	-DLUA_CFLAGS=-I$(STAGING_DIR)/usr/include
 else
 LIBUBOX_CONF_OPTS += -DBUILD_LUA=OFF