Bluetooth: host: free the adv instance if start legacy advertise fail
Bluetooth: host: free the adv instance if start legacy advertise fail

the adv instance should be delete correctly if advertise fail,
Otherwise the instance will unable to allocate if start the legacy again

Signed-off-by: chao an <218d4e837dd886ea0ff93702c797a8007ccb76b5@xiaomi.com>

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