RDMA/irdma: Remove the unnecessary variable saddr

Firstly the variable saddr was to check the type of a network. Now the
variable net_type is used to do the same work. So it is removed.

Link: https://lore.kernel.org/r/20220223024252.3873736-3-yanjun.zhu@linux.dev


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