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

Impact: Move variable declaration as far inner as possible.

Fix this sparse warning:
  drivers/net/igb/igb_main.c:1895:21: warning: symbol 'j' shadows an earlier one
  drivers/net/igb/igb_main.c:1855:16: originally declared here
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/igb/igb_main.c

@@ -1971,7 +1971,7 @@ static void igb_configure_rx(struct igb_adapter *adapter)
 	struct e1000_hw *hw = &adapter->hw;
 	u32 rctl, rxcsum;
 	u32 rxdctl;
-	int i, j;
+	int i;
 
 	/* disable receives while setting up the descriptors */
 	rctl = rd32(E1000_RCTL);
@@ -1986,7 +1986,7 @@ static void igb_configure_rx(struct igb_adapter *adapter)
 	 * the Base and Length of the Rx Descriptor Ring */
 	for (i = 0; i < adapter->num_rx_queues; i++) {
 		struct igb_ring *ring = &adapter->rx_ring[i];
-		j = ring->reg_idx;
+		int j = ring->reg_idx;
 		rdba = ring->dma;
 		wr32(E1000_RDBAL(j),
 		     rdba & 0x00000000ffffffffULL);