RDS: introduce rds_conn_connect_if_down()

A few paths had the same block of code to queue a connection's connect work if
it was in the right state.  Let's move this in to a helper function.

Signed-off-by: Zach Brown <zach.brown@oracle.com>
diff --git a/net/rds/connection.c b/net/rds/connection.c
index 180b83a..5bd96d53 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -540,6 +540,18 @@
 EXPORT_SYMBOL_GPL(rds_conn_drop);
 
 /*
+ * If the connection is down, trigger a connect. We may have scheduled a
+ * delayed reconnect however - in this case we should not interfere.
+ */
+void rds_conn_connect_if_down(struct rds_connection *conn)
+{
+	if (rds_conn_state(conn) == RDS_CONN_DOWN &&
+	    !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
+		queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
+}
+EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
+
+/*
  * An error occurred on the connection
  */
 void