mesh: Skip fast-association when using connect_without_scan

mesh: Skip fast-association when using connect_without_scan

The mesh group addition was designed to use wpa_s->connect_without_scan
to skip a scan. That path was skipped if wpa_supplicant_fast_associate()
allowed previous scan results to be used. This could result in undesired
double-initialization attempt for the mesh interface. Avoid this by not
using wpa_supplicant_fast_associate() when wpa_s->connect_without_scan
is set.

Signed-off-by: Jouni Malinen <j@w1.fi>