staging: vchiq: call unregister_chrdev_region() when driver registration fails

This undoes the previous call to alloc_chrdev_region() on failure,
and is probably what was meant originally given the label name.

Signed-off-by: Marcelo Diop-Gonzalez <marcgonzalez@google.com>
Cc: stable <stable@vger.kernel.org>
Fixes: 187ac53e ("staging: vchiq_arm: rework probe and init functions")
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20191203153921.70540-1-marcgonzalez@google.com


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