Fix a crash in page_dir_find_owner_slot if an adaptive hash index search coincides with purge or an insert


innobase/btr/btr0sea.c:
  Fix a crash in page_dir_find_owner_slot if an adaptive hash index search coincides with purge or an insert
innobase/include/btr0sea.h:
  Fix a crash in page_dir_find_owner_slot if an adaptive hash index search coincides with purge or an insert