ixgbe: remove an useless check in VF RSS

ixgbe: remove an useless check in VF RSS

To follow up the comments from Pawel Wodkowski, remove this unnecessary check,
as check_mq_mode has already check the queue number in device configure stage,
if the queue number of vf is not correct, it will return error code and exit,
so it doesn't need check again here in device start stage (note: pf_host_configure
is called in device start stage).

Fixes: 42d2f78abcb77 ("configure VF RSS")

Suggested-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>