net/mlx4_en: Fix wrong indentation

Use tabs instead of spaces before if statement, no functional change.

Fixes: e7c1c2c46201 ("mlx4_en: Added self diagnostics test implementation")
Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -1023,7 +1023,7 @@ xdp_drop:
 			goto next;
 		}
 
-                if (unlikely(priv->validate_loopback)) {
+		if (unlikely(priv->validate_loopback)) {
 			validate_loopback(priv, skb);
 			goto next;
 		}