fix bsc_sapi_n_reject(): dlci is unsigned, use uint8_t

Change-Id: I5f04f16caecb58a28e119512267999fdc18ff172
diff --git a/include/osmocom/bsc/gsm_08_08.h b/include/osmocom/bsc/gsm_08_08.h
index b46a8d3..e55bf2c 100644
--- a/include/osmocom/bsc/gsm_08_08.h
+++ b/include/osmocom/bsc/gsm_08_08.h
@@ -6,7 +6,7 @@
 
 struct gsm_subscriber_connection;
 
-void bsc_sapi_n_reject(struct gsm_subscriber_connection *conn, int dlci);
+void bsc_sapi_n_reject(struct gsm_subscriber_connection *conn, uint8_t dlci);
 void bsc_cipher_mode_compl(struct gsm_subscriber_connection *conn, struct msgb *msg, uint8_t chosen_encr);
 int bsc_compl_l3(struct gsm_subscriber_connection *conn, struct msgb *msg, uint16_t chosen_channel);
 void bsc_dtap(struct gsm_subscriber_connection *conn, uint8_t link_id, struct msgb *msg);