Instead of checking whether the source and destination are the same,
we should check if the underlying BOs are the same, since we may
be suballocating resources from the same allocation and the kernel
will fail to execute jobs if the BO list has duplicated entries.

Fixes aborts with Unreal Engine due to failed TFU jobs.

Fixes: 30f1fc25

 ('v3dv: implement TFU blits')
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <!8098>