osmux: remove spamming log message

Not very useful:

<000b> osmux.c:163 Osmux uses CID 1 from endpoint=7 (active=1)

Get rid of it.
diff --git a/openbsc/src/libmgcp/osmux.c b/openbsc/src/libmgcp/osmux.c
index 15dd613..54370ef 100644
--- a/openbsc/src/libmgcp/osmux.c
+++ b/openbsc/src/libmgcp/osmux.c
@@ -160,9 +160,6 @@
 	memcpy(msg->data, buf, rc);
 	msgb_put(msg, rc);
 
-	LOGP(DMGCP, LOGL_DEBUG, "Osmux uses CID %u from endpoint=%d (active=%d)\n",
-		endp->osmux.cid, ENDPOINT_NUMBER(endp), endp->allocated);
-
 	while ((ret = osmux_xfrm_input(endp->osmux.in, msg, endp->osmux.cid)) > 0) {
 		/* batch full, build and deliver it */
 		osmux_xfrm_input_deliver(endp->osmux.in);