staging: vc04_services: Fix an error code in vchiq_probe()

We need to set "err" on this error path.

Fixes: 187ac53e

 ("staging: vchiq_arm: rework probe and init functions")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>