cnic: Fine-tune ring init code.

Initialize the rings only during cnic_uio_open() and shut them down
during cnic_uio_close().  Check for the new bit CNIC_LCL_FL_RINGS_INITED
before checking for ring interrupt.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/cnic.h b/drivers/net/cnic.h
index ef2c25e..4816183 100644
--- a/drivers/net/cnic.h
+++ b/drivers/net/cnic.h
@@ -192,6 +192,7 @@
 	unsigned long cnic_local_flags;
 #define	CNIC_LCL_FL_KWQ_INIT		0x0
 #define	CNIC_LCL_FL_L2_WAIT		0x1
+#define	CNIC_LCL_FL_RINGS_INITED	0x2
 
 	struct cnic_dev *dev;