mgcp_common: rename to MGCP_CONN_ID_MAXLEN

So far, MGCP_CONN_ID_LENGTH was often used as exactly the length of the
Connection Identifier. To indicate this length as a maximum, introduce the
MGCP_CONN_ID_MAXLEN and use it everywhere. Keep the old name as an alias.

Change-Id: I1117003c7614e98535d5c201d002e459c01bdc3f
diff --git a/src/libosmo-mgcp-client/mgcp_client_fsm.c b/src/libosmo-mgcp-client/mgcp_client_fsm.c
index 5368ec3..da900c5 100644
--- a/src/libosmo-mgcp-client/mgcp_client_fsm.c
+++ b/src/libosmo-mgcp-client/mgcp_client_fsm.c
@@ -41,7 +41,7 @@
 	bool mgw_trans_pending;
 
 	/* Connection ID which has been assigned by he MGW */
-	char conn_id[MGCP_CONN_ID_LENGTH];
+	char conn_id[MGCP_CONN_ID_MAXLEN];
 
 	/* Local RTP connection info, the MGW will send outgoing traffic to the
 	 * ip/port specified here. The Address does not have to be choosen right
diff --git a/src/libosmo-mgcp/mgcp_conn.c b/src/libosmo-mgcp/mgcp_conn.c
index 3a5db0f..2a45b81 100644
--- a/src/libosmo-mgcp/mgcp_conn.c
+++ b/src/libosmo-mgcp/mgcp_conn.c
@@ -78,7 +78,7 @@
 		/* ensure that the generated conn_id is unique
 		 * for this endpoint */
 		if (!mgcp_conn_get_rtp(endp, id_hex)) {
-			osmo_strlcpy(id, id_hex, MGCP_CONN_ID_LENGTH);
+			osmo_strlcpy(id, id_hex, MGCP_CONN_ID_MAXLEN);
 			return 0;
 		}
 	}
diff --git a/src/libosmo-mgcp/mgcp_msg.c b/src/libosmo-mgcp/mgcp_msg.c
index a7c8b47..49d0380 100644
--- a/src/libosmo-mgcp/mgcp_msg.c
+++ b/src/libosmo-mgcp/mgcp_msg.c
@@ -450,7 +450,7 @@
 	}
 
 	/* Check for over long connection identifiers */
-	if (strlen(conn_id) > MGCP_CONN_ID_LENGTH) {
+	if (strlen(conn_id) > MGCP_CONN_ID_MAXLEN) {
 		LOGP(DLMGCP, LOGL_ERROR,
 		     "endpoint:0x%x invalid ConnectionIdentifier (too long) 0x%s\n",
 		     ENDPOINT_NUMBER(endp), conn_id);