percpu: make percpu-km set chunk->populated bitmap properly

percpu-km instantiates the whole chunk on creation and doesn't make
use of chunk->populated bitmap and leaves it as zero.  While this
currently doesn't cause any problem, the inconsistency makes it
difficult to build further logic on top of chunk->populated.  This
patch makes percpu-km fill chunk->populated on creation so that the
bitmap is always consistent.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

mm/percpu-km.c

@@ -67,6 +67,9 @@ static struct pcpu_chunk *pcpu_create_chunk(void)
 
 	chunk->data = pages;
 	chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];
+
+	bitmap_fill(chunk->populated, nr_pages);
+
 	return chunk;
 }