WPS: Reject invalid credential more cleanly

WPS: Reject invalid credential more cleanly

If WPS Registrar tries to provision a WPA/WPA2-Personal network without
including a valid Network Key, the network block cannot be used to
connect to the network. Reject such credential without adding the
network block. This makes wpa_supplicant send WSC_NACK as a response to
the invalid Credential and stop the provisioning process immediately
rather than only after trying unsuccessfully to connect to the network.

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