In module exit, dfs_parent and it's subtree were removed before
unregistering with pci. When debugfs entry for each device is attempted
to remove in pci_remove() context, they don't exist, as dfs_parent and
its children were already ripped apart.
Modified to first unregister with pci and then remove dfs_parent.
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>