Stefan Wahren <stefan.wahren@i2se.com> writes:

> The bcm2835-mailbox returns NULL instead of an error pointer, which could
> result in a NULL ptr dereference in mbox_request_channel. So fix this
> by returning a proper error pointer.
>
> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> Fixes: 0bae6af6d704 ("mailbox: Enable BCM2835 mailbox support")

Reviewed-by: Eric Anholt <eric@anholt.net>