RDMA/irdma: Use net_type to check network type

The member variable net_type is to check the type of network.

Link: https://lore.kernel.org/r/20220223024252.3873736-2-yanjun.zhu@linux.dev


Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>