[][MAC80211][hostapd][Initialize the value of center_segment1]

[Description]
Add center_segment1's initial value in case of center_segment1 is unused.

[Release-log]
N/A

Change-Id: I581c6c83234e8ef07e538d0c9a3172863d243caf
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7303280
1 file changed