Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "10 patches.

  Subsystems affected by this patch series: ipc, MAINTAINERS, and mm
  (vmscan, debug, pagemap, kmemleak, and selftests)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kselftest/vm: revert "tools/testing/selftests/vm/userfaultfd.c: use swap() to make code cleaner"
  MAINTAINERS: update rppt's email
  mm/kmemleak: avoid scanning potential huge holes
  ipc/sem: do not sleep with a spin lock held
  mm/pgtable: define pte_index so that preprocessor could recognize it
  mm/page_table_check: check entries at pmd levels
  mm/khugepaged: unify collapse pmd clear, flush and free
  mm/page_table_check: use unsigned long for page counters and cleanup
  mm/debug_vm_pgtable: remove pte entry from the page table
  Revert "mm/page_isolation: unset migratetype directly for non Buddy page"

diff --cc MAINTAINERS
Simple merge