osmux: Allocate rate counters during initialization of osmux conn

Let's not delay allocation of rate counters until the osmux conn is
fully enabled, since we may want to count stuff before that point in
time.

Fixes crash accessing null conn->osmux.ctrg in
MGCP_Test.TC_two_crcx_and_rtp_osmux_bidir.

Change-Id: Ic31d3567f4d24e628f8983d8362e5c7c2f66ec02
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index e748c5b..711ca31 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -1003,8 +1003,7 @@
 	conn->osmux.state = OSMUX_STATE_DISABLED;
 	/* If X-Osmux (remote CID) was received (-1 is wilcard), alloc next avail CID as local CID */
 	if (remote_osmux_cid >= -1) {
-		conn->osmux.state = OSMUX_STATE_ACTIVATING;
-		if (conn_osmux_allocate_local_cid(conn) == -1) {
+		if (osmux_init_conn(conn) < 0) {
 			rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_NO_OSMUX));
 			goto error2;
 		}