BOOL ldm_validate_partition_table (struct block_device * bdev);
This function provides a weak test to decide whether the device is a dynamic disk or not. It looks for an MS-DOS-style partition table containing at least one partition of type 0x42 (formerly SFS, now used by Windows for dynamic disks).
N.B. The only possible error can come from the read_dev_sector and that is only likely to happen if the underlying device is strange. If that IS the case we should return zero to let someone else try.
TRUE bdev is a dynamic disk FALSE bdev is not a dynamic disk, or an error occurred