net/iavf: fix QFI field bit check for GTPU EH

net/iavf: fix QFI field bit check for GTPU EH

If GTPU Extension header has no pdu_type setting, the parsed value of
gtp_psc_spec->hdr.type will be 0, which is same as IAVF_GTPU_EH_DWLINK.
Thus, for this case, we should check gtp_psc_mask->hdr.type instead,
to set QFI field bit of GTPU_EH first.

Fixes: cd212c466992 ("net/iavf: fix QFI fields of GTPU UL/DL for flow director")
Cc: stable@dpdk.org
Signed-off-by: Junfeng Guo <junfeng.guo@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>