btrfs: sysfs: Fix error path kobject memory leak

If a call to kobject_init_and_add() fails we must call kobject_put()
otherwise we leak memory.

Calling kobject_put() when kobject_init_and_add() fails drops the
refcount back to 0 and calls the ktype release method (which in turn
calls the percpu destroy and kfree).

Add call to kobject_put() in the error path of call to
kobject_init_and_add().

Cc: stable@vger.kernel.org # v4.4+
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -3882,8 +3882,7 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags)
 				    info->space_info_kobj, "%s",
 				    alloc_name(space_info->flags));
 	if (ret) {
-		percpu_counter_destroy(&space_info->total_bytes_pinned);
-		kfree(space_info);
+		kobject_put(&space_info->kobj);
 		return ret;
 	}