myri10ge: fix error checking and return value in myri10ge_allocate_rings

Fix a missing error check in myri10ge_allocate_rings() and set status
to -ENOMEM before all actual allocations so that the error path returns
what it should.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/myri10ge/myri10ge.c

@@ -1456,6 +1456,8 @@ static int myri10ge_allocate_rings(struct net_device *dev)
 	status = myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_SEND_RING_SIZE, &cmd, 0);
 	tx_ring_size = cmd.data0;
 	status |= myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_RX_RING_SIZE, &cmd, 0);
+	if (status != 0)
+		return status;
 	rx_ring_size = cmd.data0;
 
 	tx_ring_entries = tx_ring_size / sizeof(struct mcp_kreq_ether_send);
@@ -1463,6 +1465,8 @@ static int myri10ge_allocate_rings(struct net_device *dev)
 	mgp->tx.mask = tx_ring_entries - 1;
 	mgp->rx_small.mask = mgp->rx_big.mask = rx_ring_entries - 1;
 
+	status = -ENOMEM;
+
 	/* allocate the host shadow rings */
 
 	bytes = 8 + (MYRI10GE_MAX_SEND_DESC_TSO + 4)