sh_eth: call sh_eth_tsu_get_offset() from TSU register accessors

With sh_eth_tsu_get_offset() now actually returning TSU register's offset,
we  can at last use it in sh_eth_tsu_{read|write}(). Somehow this saves 248
bytes of object code with AArch64 gcc 4.8.5... :-)

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/sh_eth.c

@@ -447,7 +447,7 @@ static u16 sh_eth_tsu_get_offset(struct sh_eth_private *mdp, int enum_index)
 static void sh_eth_tsu_write(struct sh_eth_private *mdp, u32 data,
 			     int enum_index)
 {
-	u16 offset = mdp->reg_offset[enum_index];
+	u16 offset = sh_eth_tsu_get_offset(mdp, enum_index);
 
 	if (WARN_ON(offset == SH_ETH_OFFSET_INVALID))
 		return;
@@ -457,7 +457,7 @@ static void sh_eth_tsu_write(struct sh_eth_private *mdp, u32 data,
 
 static u32 sh_eth_tsu_read(struct sh_eth_private *mdp, int enum_index)
 {
-	u16 offset = mdp->reg_offset[enum_index];
+	u16 offset = sh_eth_tsu_get_offset(mdp, enum_index);
 
 	if (WARN_ON(offset == SH_ETH_OFFSET_INVALID))
 		return ~0U;