net/mlx4: remove unused array zero_gid[]

zero_gid is not used, so remove this redundant array.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -39,8 +39,6 @@
 
 #include "mlx4.h"
 
-static const u8 zero_gid[16];	/* automatically initialized to 0 */
-
 int mlx4_get_mgm_entry_size(struct mlx4_dev *dev)
 {
 	return 1 << dev->oper_log_mgm_entry_size;