[][openvswitch][mt7986][Fix some code defect]

[Description]
Fix crash issue when do over night test in ovs_packet_cmd_execute()
Change to forward multicast packet unregistered to all vports instead of drop

[Release-log]
N/A

Change-Id: Iecc153a877cb1a5bf3ed6814e709110f0390b8d0
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7028152
1 file changed