userfaultfd: non-cooperative: optimize mremap_userfaultfd_complete()

userfaultfd: non-cooperative: optimize mremap_userfaultfd_complete()

Optimize the mremap_userfaultfd_complete() interface to pass only the
vm_userfaultfd_ctx pointer through the stack as a microoptimization.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrea Arcangeli <[email protected]>
Reported-by: Hillf Danton <[email protected]>
Acked-by: Mike Rapoport <[email protected]>
Cc: "Dr. David Alan Gilbert" <[email protected]>
Cc: Michael Rapoport <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>