fix for segmentation fault in BaldeRF

targets/ARCH/BLADERF/USERSPACE/LIB/bladerf_lib.c

@@ -1080,6 +1080,7 @@ int device_init(openair0_device *device, openair0_config_t *openair0_cfg) {
   device->trx_set_freq_func    = trx_brf_set_freq;
   device->trx_set_gains_func   = trx_brf_set_gains;
   device->openair0_cfg = openair0_cfg;
+  device->priv = (void *)brf;
 
   calibrate_rf(device);