staging/rdma/hfi1: Remove unnecessary duplicated variable

struct hfi1_devdata contained 2 variables which represented the numa
node the device is attached to.  Remove the duplicated one.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>