btrfs: sysfs: normalize the error handling branch in btrfs_init_sysfs()

btrfs: sysfs: normalize the error handling branch in btrfs_init_sysfs()

commit 09b2c76b090b5b0af8420b1ce068779556b0c452 upstream.

Although kset_unregister() can eventually remove all attribute files,
explicitly rolling back with the matching function makes the code logic
look clearer.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>