Bluetooth: controller: split: Move invalidation of connection handle
Bluetooth: controller: split: Move invalidation of connection handle

Move invalidation of connection handle when flushing TX buffers into
LLL context. Otherwise, LLL may or may not see invalidated handle
depending on mayfly scheduling.

Signed-off-by: Wolfgang Puffitsch <f148e6efbb74c70a1ee845a87fa7616913a99a4b@demant.com>

galak/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,finikorg/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr