netdev: Make ethtool_ops::set_flags() return -EINVAL for unsupported flags

The documented error code for attempts to set unsupported flags (or
to clear flags that cannot be disabled) is EINVAL, not EOPNOTSUPP.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index 0809f6c..29e293f 100644
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -10983,7 +10983,7 @@
 	int rc = 0;
 
 	if (data & ~(ETH_FLAG_LRO | ETH_FLAG_RXHASH))
-		return -EOPNOTSUPP;
+		return -EINVAL;
 
 	if (bp->recovery_state != BNX2X_RECOVERY_DONE) {
 		printk(KERN_ERR "Handling parity error recovery. Try again later\n");