spidernet: Replace literal with const

Replace literal with const; add bit definitions.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/spider_net.c b/drivers/net/spider_net.c
index 9d3ae35..f5abb52 100644
--- a/drivers/net/spider_net.c
+++ b/drivers/net/spider_net.c
@@ -1235,7 +1235,7 @@
 		goto bad_desc;
 	}
 
-	if (hwdescr->dmac_cmd_status & 0xfcf4) {
+	if (hwdescr->dmac_cmd_status & SPIDER_NET_DESCR_BAD_STATUS) {
 		dev_err(&card->netdev->dev, "bad status, cmd_status=x%08x\n",
 			       hwdescr->dmac_cmd_status);
 		pr_err("buf_addr=x%08x\n", hw_buf_addr);