Improve ntfs_device_size_get for file

[kgermanov]

For calculation size of device if passed file instead of device (https://github.com/tuxera/ntfs-3g/blob/edge/libntfs-3g/device.c#L599):

	/*
	 * We couldn't figure it out by using a specialized ioctl,
	 * so do binary search to find the size of the device.
	 */
	low = 0LL;
	for (high = 1024LL; !ntfs_device_offset_valid(dev, high); high <<= 1)
		low = high;
	while (low < high - 1LL) {
		const s64 mid = (low + high) / 2;
		if (!ntfs_device_offset_valid(dev, mid))
			low = mid;
		else
			high = mid;
	}
	dev->d_ops->seek(dev, 0LL, SEEK_SET);

But there is IO callback stat(https://github.com/tuxera/ntfs-3g/blob/edge/include/ntfs-3g/device.h#L113) whose contains size of file.
So we can call this callback for avoid count of random read.