drivers/net/s2io.c: fix sparse warning: symbol shadows an earlier one

Impact: Remove redundant inner scope variable.

Fix this sparse warning:
  drivers/net/s2io.c:7223:21: warning: symbol 'i' shadows an earlier one
  drivers/net/s2io.c:7184:13: originally declared here

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 5cd2291..16868b7 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -7220,7 +7220,6 @@
 
 	/* Initialise napi */
 	if (config->napi) {
-		int i;
 		if (config->intr_type ==  MSI_X) {
 			for (i = 0; i < sp->config.rx_ring_num; i++)
 				napi_enable(&sp->mac_control.rings[i].napi);