Both of these test cases were leaving out BSS entries with active PBC
mode at the end of the test. This could result in the next text case
failing, e.g., in "ap_wps_pbc_overlap_2ap grpform_ext_listen" and
"ap_wps_pbc_overlap_2sta grpform_ext_listen" sequences. Fix this by
flushing the scan results more carefully at the end of the PBC overlap
test cases.
Signed-off-by: Jouni Malinen <j@w1.fi>