btrfs: fix memory leak in update_space_info failure path

commit 896533a7da929136d0432713f02a3edffece2826 upstream.

If we fail to add the space_info kobject, we'll leak the memory
for the percpu counter.

Fixes: 6ab0a2029c (btrfs: publish allocation data in sysfs)
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5909ae8..e46e7fb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3984,6 +3984,7 @@
 				    info->space_info_kobj, "%s",
 				    alloc_name(found->flags));
 	if (ret) {
+		percpu_counter_destroy(&found->total_bytes_pinned);
 		kfree(found);
 		return ret;
 	}