net/mlx5e: Add missing release firmware call

Once driver finishes flashing the firmware image, it should release it.

Fixes: 9c8bca26 ("mlx5: Move firmware flash implementation to devlink")
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/devlink.c

@@ -23,7 +23,10 @@ static int mlx5_devlink_flash_update(struct devlink *devlink,
 	if (err)
 		return err;
 
-	return mlx5_firmware_flash(dev, fw, extack);
+	err = mlx5_firmware_flash(dev, fw, extack);
+	release_firmware(fw);
+
+	return err;
 }
 
 static u8 mlx5_fw_ver_major(u32 version)