package/weston: disable -NDEBUG

Per upstream -NDEBUG should not be set for any builds:
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/643#note_958356

Fixes:
http://autobuild.buildroot.net/results/f42/f420890de1b52786f8cf5f2922b69c909162eaa1/

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/weston/weston.mk

@@ -19,6 +19,8 @@ WESTON_CONF_OPTS = \
 	-Dcolor-management-colord=false \
 	-Dremoting=false
 
+WESTON_CFLAGS="$(TARGET_CFLAGS) -UNDEBUG"
+
 # Uses VIDIOC_EXPBUF, only available from 3.8+
 ifeq ($(BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8),y)
 WESTON_CONF_OPTS += -Dsimple-clients=dmabuf-v4l