[][MAC80211][hostapd][Fix mtk vendor subcmd EDCCA control issue]

[Description]
Fix EDCCA control subcmd cause interface down issue.

If wifi driver didn't support EDCCA control vendor command,
nl80211_configure_edcca_threshold() will return error which cause hostapd
to bring down the interface in current implementation. It shall return 0 if
wifi driver didn't support EDCCA control vendor command.

[Release-log]
N/A

Change-Id: I71143e44b43892702e3325b2fcff302631b4baf1
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6244040
1 file changed