percpu: fix starting offset for chunk statistics traversal

This patch fixes the starting offset used when scanning chunks to
compute the chunk statistics. The value start_offset (and end_offset)
are managed in bytes while the traversal occurs over bits. Thus for the
reserved and dynamic chunk, it may incorrectly skip over the initial
allocations.
Signed-off-by: NDennis Zhou <dennisszhou@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

mm/percpu-stats.c

@@ -73,7 +73,7 @@ static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk,
 		     last_alloc + 1 : 0;
 
 	as_len = 0;
-	start = chunk->start_offset;
+	start = chunk->start_offset / PCPU_MIN_ALLOC_SIZE;
 
 	/*
 	 * If a bit is set in the allocation map, the bound_map identifies