Bugfix: if the cc2420_cca() function wasn't able to turn on the radio properly, it should turn it off again if it was off before.
Bugfix: if the cc2420_cca() function wasn't able to turn on the radio properly, it should turn it off again if it was off before.

arurke/contiki,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,bluerover/6lbr,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,bluerover/6lbr,MohamedSeliem/contiki,bluerover/6lbr,MohamedSeliem/contiki,arurke/contiki,bluerover/6lbr,bluerover/6lbr,MohamedSeliem/contiki,bluerover/6lbr,arurke/contiki,bluerover/6lbr,MohamedSeliem/contiki,MohamedSeliem/contiki