IB/qib, IB/hfi1: Fix grh creation in ud loopback

Instead of copying the actual GRH of type struct ib_grh, existing code
copies the struct ib_global_route into the sge. This patch fixes that
and constructs the actual GRH from ib_global_route and copies the GRH
into the sge.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Dean Luick <dean.luick@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>