myri10ge: Stop scaring people when DCA is built but absent

Stop scaring people with what looks like a fatal message when DCA support
is compiled into their kernel, but the DCA device is not present.
Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/myri10ge/myri10ge.c

@@ -1060,6 +1060,7 @@ static void myri10ge_setup_dca(struct myri10ge_priv *mgp)
 	}
 	err = dca_add_requester(&pdev->dev);
 	if (err) {
+		if (err != -ENODEV)
 			dev_err(&pdev->dev,
 				"dca_add_requester() failed, err=%d\n", err);
 		return;