net/ice/base: propagate errors from functions

net/ice/base: propagate errors from functions

There could be an error returned from ice_fill_adv_dummy_packet()
so we need to propagate that to the caller. Additionally, the
call to ice_flow_xtract_pkt_flags() could also return an error so
we need to propagate it as well.

Also add in the correct offsets for GENEVE and VXLAN_GPE to the
dummy packets.

Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Qiming Yang <qiming.yang@intel.com>