NTB: Rate limit ntb_qp_link_work

When the ntb transport is connecting and waiting for the peer, the debug
console receives lots of debug level messages about the remote qp link
status being down.  Rate limit those messages.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 2efd1ea..8ce0bf6 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -850,7 +850,7 @@
 
 	/* query remote spad for qp ready bits */
 	ntb_peer_spad_read(nt->ndev, QP_LINKS);
-	dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
+	dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 
 	/* See if the remote side is up */
 	if (val & BIT(qp->qp_num)) {