mremap: simplify the "overlap" check in mremap_to()
mremap: simplify the "overlap" check in mremap_to()

Minor, but this check is overcomplicated.  Two half-intervals do NOT
overlap if END1 <= START2 || END2 <= START1, mremap_to() just needs to
negate this check.

Signed-off-by: Oleg Nesterov <20b70f0af00562e63758b9ee42012ecc96c58590@redhat.com>
Acked-by: David Rientjes <d8cd2994e15bc61ddb2b113030bda55eebc3a0fe@google.com>
Cc: Benjamin LaHaise <b05c66fa21e46731bb89a779db663748f3df8f6a@kvack.org>
Cc: Hugh Dickins <d3abdf3e2800e6cb849f11b81e6eb50b34d96431@google.com>
Cc: Jeff Moyer <cd6badf7869d996b866599075536a600ed1910b5@redhat.com>
Cc: Kirill A. Shutemov <eec72676ad9a62f2727dfed6d270d98c0d02adec@linux.intel.com>
Cc: Laurent Dufour <a59ffce977ae3d39bdc87f81ff88b229ad58db88@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.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