mm: nobootmem: fix sign extend problem in __free_pages_memory()

mm: nobootmem: fix sign extend problem in __free_pages_memory()

Systems with 8 TBytes of memory or greater can hit a problem where only
the the first 8 TB of memory shows up.  This is due to "int i" being
smaller than "unsigned long start_aligned", causing the high bits to be
dropped.

The fix is to change `i' to unsigned long to match start_aligned
and end_aligned.

Thanks to Jack Steiner for assistance tracking this down.

Signed-off-by: Russ Anderson <[email protected]>
Cc: Jack Steiner <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Gavin Shan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>