mm/hmm: hmm_pfns_bad() was accessing wrong struct

The private field of mm_walk struct point to an hmm_vma_walk struct and
not to the hmm_range struct desired.  Fix to get proper struct pointer.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jérôme Glisse <[email protected]>
Cc: Evgeny Baskakov <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: Mark Hairgrove <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Jérôme Glisse

mm/hmm.c

@@ -336,7 +336,8 @@ static int hmm_pfns_bad(unsigned long addr,
 			unsigned long end,
 			struct mm_walk *walk)
 {
-	struct hmm_range *range = walk->private;
+	struct hmm_vma_walk *hmm_vma_walk = walk->private;
+	struct hmm_range *range = hmm_vma_walk->range;
 	hmm_pfn_t *pfns = range->pfns;
 	unsigned long i;