percpu: stop leaking bitmap metadata blocks

The commit ca460b3c9627 ("percpu: introduce bitmap metadata blocks")
introduced bitmap metadata blocks. These metadata blocks are allocated
whenever a new chunk is created, but they are never freed. Fix it.

Fixes: ca460b3c9627 ("percpu: introduce bitmap metadata blocks")
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dennis Zhou <dennis@kernel.org>

mm/percpu.c

@@ -1212,6 +1212,7 @@ static void pcpu_free_chunk(struct pcpu_chunk *chunk)
 {
 	if (!chunk)
 		return;
+	pcpu_mem_free(chunk->md_blocks);
 	pcpu_mem_free(chunk->bound_map);
 	pcpu_mem_free(chunk->alloc_map);
 	pcpu_mem_free(chunk);