Fix for logical bug in calculating sector number beyond 2TB hdd size.

There is a logical error in EIO_ROUND_SECTOR macro calculation.
The mask value used to align sector number to 8 sector boundary, is of 32 bit.

Any value for "sector" greater that 32 bit is getting truncated to smaller value
causing wrong calculation in eio_new_job for "job_io_regions.cache.sector".

This lead to the following error. "attempt to access beyond size of device."
Fix is to convert this 32 bit mask to 64 bit mask.

I have tested the fix by running mkfs.ext4 and doing read/writes beyond 2TB sector
on cache.

Signed off by abhansali@stec-inc.com
Merge pull request #29 from bhansaliakhil/master

Fix for "Partitioned cache device causes "attempt to access beyond end of device" and kernel panic" for EnhanceIO.