net: ethernet: gianfar_ethtool: remove redundant variable last_rule_idx

Variable last_rule_idx is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'last_rule_idx' set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar_ethtool.c

@@ -740,7 +740,6 @@ static void ethflow_to_filer_rules (struct gfar_private *priv, u64 ethflow)
 static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
 				       u64 class)
 {
-	unsigned int last_rule_idx = priv->cur_filer_idx;
 	unsigned int cmp_rqfpr;
 	unsigned int *local_rqfpr;
 	unsigned int *local_rqfcr;
@@ -819,7 +818,6 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
 	}
 
 	priv->cur_filer_idx = l - 1;
-	last_rule_idx = l;
 
 	/* hash rules */
 	ethflow_to_filer_rules(priv, ethflow);