V4L/DVB (13380): sms-cards: make id unsigned in sms_get_board()

Make id signed so we can't get an invalid pointer when we pass a negative
id.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/siano/sms-cards.h b/drivers/media/dvb/siano/sms-cards.h
index 38f062f..8f19fc0 100644
--- a/drivers/media/dvb/siano/sms-cards.h
+++ b/drivers/media/dvb/siano/sms-cards.h
@@ -81,7 +81,7 @@
 	int led_power, led_hi, led_lo, lna_ctrl, rf_switch;
 };
 
-struct sms_board *sms_get_board(int id);
+struct sms_board *sms_get_board(unsigned id);
 
 extern struct smscore_device_t *coredev;