ionic: update eid test for overflow

Fix up our comparison to better handle a potential (but largely
unlikely) wrap around.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_lif.c

@@ -719,7 +719,7 @@ static bool ionic_notifyq_service(struct ionic_cq *cq,
 	eid = le64_to_cpu(comp->event.eid);
 
 	/* Have we run out of new completions to process? */
-	if (eid <= lif->last_eid)
+	if ((s64)(eid - lif->last_eid) <= 0)
 		return false;
 
 	lif->last_eid = eid;