Re-order wpa_sm_rx_eapol() to first go through all EAPOL (802.1X) header
validation steps using the original message buffer and re-allocate and
copy the frame only if this is a valid EAPOL frame that contains an
EAPOL-Key. This makes the implementation easier to understand and saves
unnecessary memory allocations and copying should other types of EAPOL
frames get here.
Signed-off-by: Jouni Malinen <j@w1.fi>