net/iavf: relax RSS virtual channel commands

net/iavf: relax RSS virtual channel commands

Kernel PF may not respond to virtual channel commands
VIRTCHNL_OP_GET_RSS_HENA_CAPS and VIRTCHNL_OP_SET_RSS_HENA, which
will cause VF to fail to start.

RSS offload type configuration is not a necessary feature for VF,
so in order to improve VF compatibility, in this patch the PMD will
ignore the error result of above two commands and will print warnings
instead.

Fixes: 5a038d19962d ("net/iavf: fix RSS configuration on i40e VF")
Cc: stable@dpdk.org
Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>