net80211 drivers: fix ieee80211_init_channels() usage
Fix out-of-bounds read (all) / write (11n capable) for drivers
that are using ieee80211_init_channels() to initialize channel list.
Tested with:
- RTL8188EU, STA mode.
- RTL8188CUS, STA mode.
- WUSB54GC, HOSTAP mode.
Approved by: adrian (mentor)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D4818