RDMA/irdma: optimize rx path by removing unnecessary copy

In the function irdma_post_recv, the function irdma_copy_sg_list is
not needed since the struct irdma_sge and ib_sge have the similar
member variables. The struct irdma_sge can be replaced with the
struct ib_sge totally.

This can increase the rx performance of irdma.

Link: https://lore.kernel.org/r/20211030104226.253346-1-yanjun.zhu@linux.dev


Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>