allocate_flower_entry: should check for null deref

allocate_flower_entry does not check for allocation success, but tries
to deref the result. I only moved the spin_lock under null check, because
 the caller is checking allocation's status at line 652.
Signed-off-by: NNavid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c

@@ -67,7 +67,8 @@ static struct ch_tc_pedit_fields pedits[] = {
 static struct ch_tc_flower_entry *allocate_flower_entry(void)
 {
 	struct ch_tc_flower_entry *new = kzalloc(sizeof(*new), GFP_KERNEL);
-	spin_lock_init(&new->lock);
+	if (new)
+		spin_lock_init(&new->lock);
 	return new;
 }