cdrom: gdrom: initialize global variable at init time

As Peter points out, if we were to disconnect and then reconnect this
driver from a device, the "global" state of the device would contain odd
values and could cause problems.  Fix this up by just initializing the
whole thing to 0 at probe() time.

Ideally this would be a per-device variable, but given the age and the
total lack of users of it, that would require a lot of s/./->/g changes
for really no good reason.

Reported-by: Peter Rosin <peda@axentia.se>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/YJP2j6AU82MqEY2M@kroah.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>