RDMA/mana_ib: Fix missing ret value

Set ret to -ENODEV when netdev_master_upper_dev_get_rcu returns NULL.

Fixes: 8b184e4f1c32 ("RDMA/mana_ib: Enable RoCE on port 1")
Link: https://lore.kernel.org/r/1713881751-21621-1-git-send-email-kotaranov@linux.microsoft.com
Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
1 file changed