mt76x2: remove unnecessary break in mt76x2_mac_process_tx_rate()

Remove unnecessary break statement in the default case of bw switch
block in mt76x2_mac_process_tx_rate routine
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mediatek/mt76/mt76x2_mac.c

@@ -410,7 +410,6 @@ mt76x2_mac_process_tx_rate(struct ieee80211_tx_rate *txrate, u16 rate,
 		break;
 	default:
 		return -EINVAL;
-		break;
 	}
 
 	if (rate & MT_RXWI_RATE_SGI)