net/ncsi: Fix the payload copying for the request coming from Netlink

The request coming from Netlink should use the OEM generic handler.

The standard command handler expects payload in bytes/words/dwords
but the actual payload is stored in data if the request is coming from Netlink.

Signed-off-by: Justin Lee <justin.lee1@dell.com>
Reviewed-by: Vijay Khemka <vijaykhemka@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>