driver core: don't always lock parent in shutdown

driver core: don't always lock parent in shutdown

Don't lock a parent device unless it is needed in device_shutdown. This
is in preparation for making device shutdown asynchronous, when it will
be needed to allow children of a common parent to shut down
simultaneously.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240822202805.6379-2-stuart.w.hayes@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>