Description of problem:

Given a device with more than 2147483648 sectors (i.e. 2^31), blockdev --getsize
prints the size as a negative number.

Version-Release number of selected component (if applicable):

util-linux-2.13-0.46.fc6

How reproducible:

Steps to Reproduce:
1. Find a device that is bigger than 1TB (or stitch one together via dmsetup)
2. blockdev --getsize /the/device
  
Actual results:

A negative number

Expected results:

A positive number

Additional info:

The BLKGETSIZE ioctl returns a 32-bit unsigned value, but the blockdev program
is using a signed integer, so any value over 2^31 flips negative.