The check for node_boot_start is bogus because we start freeing at the
corresponding pfn. So check if the pfn is properly aligned instead in a more
readable way and adjust the documentation.
Also remove an unneeded accounting variable.
Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>