drivers/net/cxgb3: fix sparse warning: symbol shadows an earlier one

Impact: Move variable declaration as close to usage as possible.

Fix this sparse warning:
  drivers/net/cxgb3/cxgb3_main.c:1586:21: warning: symbol 'cap' shadows an earlier one
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Acked-by: NDivy Le Ray <divy@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/cxgb3/cxgb3_main.c

@@ -1565,7 +1565,6 @@ static int speed_duplex_to_caps(int speed, int duplex)
 
 static int set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 {
-	int cap;
 	struct port_info *p = netdev_priv(dev);
 	struct link_config *lc = &p->link_config;
 
@@ -1575,7 +1574,7 @@ static int set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 		 * being requested.
 		 */
 		if (cmd->autoneg == AUTONEG_DISABLE) {
-			cap = speed_duplex_to_caps(cmd->speed, cmd->duplex);
+			int cap = speed_duplex_to_caps(cmd->speed, cmd->duplex);
 			if (lc->supported & cap)
 				return 0;
 		}