net/ncsi: fix restricted cast warning of sparse

Sparse reports:
net/ncsi/ncsi-rsp.c:406:24: warning: cast to restricted __be32
net/ncsi/ncsi-manage.c:732:33: warning: cast to restricted __be32
net/ncsi/ncsi-manage.c:756:25: warning: cast to restricted __be32
net/ncsi/ncsi-manage.c:779:25: warning: cast to restricted __be32

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>