net: openthread: style adjustments in `radio.c`
net: openthread: style adjustments in `radio.c`

Avoid splitting lines when possible while keeping length below 100
chars. Some other minor style corrections.

Signed-off-by: Eduardo Montoya <c6d924925ebf82d772472f7877e771cedf439387@nordicsemi.no>

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