Fix REMOVE_NETWORK to not run operations with invalid current_ssid

Fix REMOVE_NETWORK to not run operations with invalid current_ssid

If the REMOVE_NETWORK command is used to delete the currently connected
network, some operations were run between removing the network and
clearing of wpa_s->current_ssid. This left wpa_s->current_ssid pointing
to freed memory and should any operation end up using it before the
pointer gets cleared, freed memory could be references. Avoid this by
removing the network only after having completed the operations that
clear wpa_s->current_ssid.

Signed-hostap: Deepthi Gowri <deepthi@codeaurora.org>
intended-for: hostap-1