tools/vm/page-types.c: fix "kpagecount returned fewer pages than expected" failures

Because kpagecount_read() fakes success if map counts are not being
collected, clamp the page count passed to it by walk_pfn() to the pages
value returned by the preceding call to kpageflags_read().

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 7f1d23e ("tools/vm/page-types.c: include shared map counts")
Signed-off-by: Anthony Yznaga <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Anthony Yznaga

tools/vm/page-types.c

@@ -701,7 +701,7 @@ static void walk_pfn(unsigned long voffset,
 		if (kpagecgroup_read(cgi, index, pages) != pages)
 			fatal("kpagecgroup returned fewer pages than expected");
 
-		if (kpagecount_read(cnt, index, batch) != pages)
+		if (kpagecount_read(cnt, index, pages) != pages)
 			fatal("kpagecount returned fewer pages than expected");
 
 		for (i = 0; i < pages; i++)