P2P: Fix re-invoked client interface completion on data connection

P2P: Fix re-invoked client interface completion on data connection

This was already working for the case where a separate group interface
is used due to the recent commit
328f49acfe961a212e89e750516d2e2cc320765f ('P2P: Complete group formation
on client data connection'). However, the case of no separate group
interface was used did not clear the interface state properly on data
connection. Fix this by setting the group formation information in
wpas_start_p2p_client().

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>