staging: vme: fix loop condition

Fix loop condition in vme_register_bridge that results in an infinite
loop in the event that device_register fails.

Signed-off-by: Manohar Vanga <manohar.vanga@cern.ch>
Acked-by: Martyn Welch <martyn.welch@ge.com>
Acked-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>