More robust timer_tick_enabled tracking

More robust timer_tick_enabled tracking

Do not set sm->timer_tick_enabled if the eloop_register_timeout() call
fails so that the next attempt to enable the timer in
eapol_enable_timer_tick() can try to recover from unexpected eloop
failures. This should not really be needed in practical use cases, but
certain out-of-memory test cases can trigger allocation failure in
eloop_register_timeout() and if that happens, the previous EAPOL
supplicant state machine implementation got pretty much completely stuck
for any operation needing the timer.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>