mm/memory.c: update comment in unmap_single_vma()
mm/memory.c: update comment in unmap_single_vma()

The described issue now occurs inside mmap_region().  And unfortunately
is still valid.

Signed-off-by: Davidlohr Bueso <4aa5652442886f3c4e77d3a743dc27e129c1613f@hp.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs