Fix CRC calculation of UDI images on LP64 platforms
Fix CRC calculation of UDI images on LP64 platforms

for example most Linux 64 bits. The reference algorithm comes from the
32 bits era and relies on a "long" type of 32 bits. That only works on
Windows 32 bits (ILP32), Windows 64 bits (LLP64) or Linux 32 bits
(LLP64).

simonowen/samdisk,simonowen/samdisk,simonowen/samdisk