amdkfd: fix an error handling bug in pqm_create_queue()

The call to kernel_queue_uninit(NULL) will trigger a BUG(), and also the
error code is incorrect.

Fixes: 45102048

 ('amdkfd: Add process queue manager module')
Reviewed-by: Oded Gabbay <oded.gabbay@amd.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>