mlx4_core: Make buffer larger to avoid overflow warning

My static checker complains that the sprintf() here can overflow.

	drivers/infiniband/hw/mlx4/main.c:1836 mlx4_ib_alloc_eqs()
	error: format string overflow. buf_size: 32 length: 69

This seems like a valid complaint.  The "dev->pdev->bus->name" string
can be 48 characters long.  I just made the buffer 80 characters instead
of 69 and I changed the sprintf() to snprintf().
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

drivers/infiniband/hw/mlx4/main.c

@@ -1803,7 +1803,7 @@ static void init_pkeys(struct mlx4_ib_dev *ibdev)
 
 static void mlx4_ib_alloc_eqs(struct mlx4_dev *dev, struct mlx4_ib_dev *ibdev)
 {
-	char name[32];
+	char name[80];
 	int eq_per_port = 0;
 	int added_eqs = 0;
 	int total_eqs = 0;
@@ -1833,8 +1833,8 @@ static void mlx4_ib_alloc_eqs(struct mlx4_dev *dev, struct mlx4_ib_dev *ibdev)
 	eq = 0;
 	mlx4_foreach_port(i, dev, MLX4_PORT_TYPE_IB) {
 		for (j = 0; j < eq_per_port; j++) {
-			sprintf(name, "mlx4-ib-%d-%d@%s",
-				i, j, dev->pdev->bus->name);
+			snprintf(name, sizeof(name), "mlx4-ib-%d-%d@%s",
+				 i, j, dev->pdev->bus->name);
 			/* Set IRQ for specific name (per ring) */
 			if (mlx4_assign_eq(dev, name, NULL,
 					   &ibdev->eq_table[eq])) {