Remove unnecessary wpa_ie_len check from wpa_parse_wpa_ie_wpa()
There is no need to have a separate "fail silently" case for wpa_ie_len
== 0. That condition does not seem to be reachable and even if it were,
the following "ie len too short" case will result in the exact same
return value.
Signed-off-by: Jouni Malinen <j@w1.fi>