mm/vmscan: do not check compaction_ready on promoted zones

We abort direct reclaim if we find the zone is ready for compaction.
Sometimes the zone is just a promoted highmem zone to force a scan of
highmem, which is not the intended zone the caller want to allocate a
page from.  In this situation, setting aborted_reclaim to indicate the
caller turned back to retry the allocation is waste of time and could
cause a loop in __alloc_pages_slowpath().

This patch does not check compaction_ready() on promoted zones to avoid
the above situation.  Only set aborted_reclaim if the caller intended
zone is ready for compaction.

Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>