wifi: virt_wifi: avoid reporting connection success with wrong SSID

In the Linux kernel, the following vulnerability has been resolved:

wifi: virt_wifi: avoid reporting connection success with wrong SSID

When user issues a connection with a different SSID than the one

virt_wifi has advertised, the __cfg80211_connect_result() will

trigger the warning: WARN_ON(bss_not_found).

The issue is because the connection code in virt_wifi does not

check the SSID from user space (it only checks the BSSID), and

virt_wifi will call cfg80211_connect_result() with WLAN_STATUS_SUCCESS

even if the SSID is different from the one virt_wifi has advertised.

Eventually cfg80211 won't be able to find the cfg80211_bss and generate

the warning.

Fixed it by checking the SSID (from user space) in the connection code.