mm: hugetlb: cleanup using paeg_huge_active()

Now we have an easy access to hugepages' activeness, so existing helpers to
get the information can be cleaned up.

[akpm@linux-foundation.org: s/PageHugeActive/page_huge_active/]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 84d10b6..f34e040 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -470,11 +470,18 @@
 #ifdef CONFIG_HUGETLB_PAGE
 int PageHuge(struct page *page);
 int PageHeadHuge(struct page *page);
+bool page_huge_active(struct page *page);
 #else
 TESTPAGEFLAG_FALSE(Huge)
 TESTPAGEFLAG_FALSE(HeadHuge)
+
+static inline bool page_huge_active(struct page *page)
+{
+	return 0;
+}
 #endif
 
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /*
  * PageHuge() only returns true for hugetlbfs pages, but not for