dsa: mv88e6xxx: Drop duplicate declaration of 'ret' variable

A duplicate declaration of 'ret' can result in hiding an error code.
Drop it.

Fixes: 17ee3e04ddbf ("net: dsa: Provide additional RMON statistics")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx.c

@@ -602,8 +602,6 @@ static void _mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds,
 		u32 high = 0;
 
 		if (s->reg >= 0x100) {
-			int ret;
-
 			ret = mv88e6xxx_reg_read(ds, REG_PORT(port),
 						 s->reg - 0x100);
 			if (ret < 0)