Partitions are trivially aligned to sector boundaries, so asking e.g.
for a partition to be aligned to a 64-byte boundary is pointless but
harmless. Treat it as such, with a warning (in case the request was
a mistake, e.g. requesting 1-byte instead of 1M-byte alignment) rather
than as an error.

Suggested by: markj
MFC after: 1 week
Sponsored by: Amazon