tests: Fix scan_specific_bssid in case Beacon frame is seen

tests: Fix scan_specific_bssid in case Beacon frame is seen

The first scan for the unknown BSSID could have been timed in a manner
that allows passive scanning to find the real AP even if that AP's
beacon interval was 1000 (e.g., heavy CPU load changed timing so that
the AP beaconing started at suitable time). The check for BSS result
entry not including Probe Response frame was comparing incorrect BSS
entries (bss2 vs. bss1) which resulted in the test case claiming failure
even when there was no unexpected Probe Response frame.

Fix this by comparing the beacon_ie and ie parameters from the same BSS
entry (bss1).

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>