Check pointers' validity before dereferencing them.
This was reported by clang's scan-build.
case SR_CONF_DEVICE_OPTIONS:
return STD_CONFIG_LIST(key, data, sdi, cg, scanopts, drvopts, devopts);
case SR_CONF_VOLTAGE_TARGET:
+ if (!devc || !devc->model)
+ return SR_ERR_ARG;
*data = std_gvar_min_max_step_array(devc->model->voltage);
break;
case SR_CONF_CURRENT_LIMIT:
+ if (!devc || !devc->model)
+ return SR_ERR_ARG;
*data = std_gvar_min_max_step_array(devc->model->current);
break;
default: