hugetlb: update hugetlbpage.txt

Commit f0f57b2 ("mm: move hugepage test examples to
tools/testing/selftests/vm") moved map_hugetlb.c, hugepage-shm.c and
hugepage-mmap.c tests into tools/testing/selftests/vm/ directory, but it
didn't update hugetlbpage.txt

Signed-off-by: Zhouping Liu <sanweidaying@gmail.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/vm/hugetlbpage.txt

@@ -299,11 +299,17 @@ map_hugetlb.c.
 *******************************************************************
 
 /*
- * hugepage-shm:  see Documentation/vm/hugepage-shm.c
+ * map_hugetlb: see tools/testing/selftests/vm/map_hugetlb.c
  */
 
 *******************************************************************
 
 /*
- * hugepage-mmap:  see Documentation/vm/hugepage-mmap.c
+ * hugepage-shm:  see tools/testing/selftests/vm/hugepage-shm.c
+ */
+
+*******************************************************************
+
+/*
+ * hugepage-mmap:  see tools/testing/selftests/vm/hugepage-mmap.c
  */