[][MAC80211][core][Fix nf_flow_offload_tuple panic issue]

[Description]
Fix nf_flow_offload_tuple panic issue.

If without this patch, kernel might panic in the nf_flow_offload_tuple() in network interface down/up test.

[Release-log]
N/A

Change-Id: Ib06425c924300fdeae9102ad7dbc6526f35ed61a
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6588559
Build: srv_hbgsm110
1 file changed