[RILMODEM] recheck status value before using it

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
[RILMODEM] recheck status also in ril_data_probe_reg_cb

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
Merge pull request #259 from jpoutiai/gprs

rilmodem gprs fixes