cnic: Return proper error code if we fail to send netlink message

to allow iSCSI connection to fail faster instead of waiting for the
long timeout.

Update version to 2.5.6.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c
index bdfe155..ea75f65 100644
--- a/drivers/net/cnic.c
+++ b/drivers/net/cnic.c
@@ -328,7 +328,7 @@
 		msleep(100);
 		retry++;
 	}
-	return 0;
+	return rc;
 }
 
 static void cnic_cm_upcall(struct cnic_local *, struct cnic_sock *, u8);