mm: hugetlb_vmemmap: fix reference to nonexistent file

The directory this file is in was renamed but the reference didn't get
updated.  Fix it.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: ee65728 ("docs: rename Documentation/vm to Documentation/mm")
Signed-off-by: Vegard Nossum <[email protected]>
Acked-by: Mike Rapoport (IBM) <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Acked-by: Mike Kravetz <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Wu XiangCheng <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: vegard

mm/hugetlb_vmemmap.h

@@ -12,7 +12,7 @@
 
 /*
  * Reserve one vmemmap page, all vmemmap addresses are mapped to it. See
- * Documentation/vm/vmemmap_dedup.rst.
+ * Documentation/mm/vmemmap_dedup.rst.
  */
 #define HUGETLB_VMEMMAP_RESERVE_SIZE	PAGE_SIZE
 #define HUGETLB_VMEMMAP_RESERVE_PAGES	(HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page))