RDMA/cma: Reenable device removal on passive side

Enable conn_id remove on the passive side after connection
establishment.  This corrects an issue where the IB driver can't be
unloaded after running applications over RDS.  The 'dev_remove' counter
does not reach 0 for established connections on the passive side.

This problem is limited to device removal, and only occurs on the
passive side if there are established connections.
Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.co.il>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/cma.c

@@ -1122,8 +1122,10 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
 	cm_id->cm_handler = cma_ib_handler;
 
 	ret = conn_id->id.event_handler(&conn_id->id, &event);
-	if (!ret)
+	if (!ret) {
+		cma_enable_remove(conn_id);
 		goto out;
+	}
 
 	/* Destroy the CM ID by returning a non-zero value. */
 	conn_id->cm_id.ib = NULL;