net/mlx4_en: Remove the redundant NULL check for the 'my_ets' object

Static analysis shows that pointer "my_ets" cannot be NULL because it
points to the object "struct ieee_ets".

Remove the extra NULL check. It is meaningless and harms the readability
of the code.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Vatoropin <[e-mail]>
Reviewed-by: Tariq Toukan <[e-mail]>
Reviewed-by: Jacob Keller <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/net/ethernet/mellanox/mlx4/en_dcb_nl.c

···
 	struct mlx4_en_priv *priv = netdev_priv(dev);
 	struct ieee_ets *my_ets = &priv->ets;
 
-	if (!my_ets)
-		return -EINVAL;
-
 	ets->ets_cap = IEEE_8021QAZ_MAX_TCS;
 	ets->cbs = my_ets->cbs;
 	memcpy(ets->tc_tx_bw, my_ets->tc_tx_bw, sizeof(ets->tc_tx_bw));