net: microchip: Remove unneeded variable ret

Remove unneeded variable ret used to store return value.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20201023092107.28065-1-vulab@iscas.ac.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/microchip/lan743x_main.c

@@ -834,14 +834,13 @@ static int lan743x_mac_init(struct lan743x_adapter *adapter)
 
 static int lan743x_mac_open(struct lan743x_adapter *adapter)
 {
-	int ret = 0;
 	u32 temp;
 
 	temp = lan743x_csr_read(adapter, MAC_RX);
 	lan743x_csr_write(adapter, MAC_RX, temp | MAC_RX_RXEN_);
 	temp = lan743x_csr_read(adapter, MAC_TX);
 	lan743x_csr_write(adapter, MAC_TX, temp | MAC_TX_TXEN_);
-	return ret;
+	return 0;
 }
 
 static void lan743x_mac_close(struct lan743x_adapter *adapter)