Userfaultfd-wp is not yet working on 32bit hosts, but it's accidentally
enabled previously.  Disable it.

Fixes: 5a281062 ("userfaultfd: wp: add WP pagetable tracking to x86")
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Link: http://lkml.kernel.org/r/20200413141608.109211-1-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>