wl1271: fix init loop timeout

The check after the loop which checks whether the initialization timed-out
was wrong.  If the initialization would succeed exactly in the 20000th time
(the value set for INIT_LOOP), the driver would bail out and claim that
initialization failed.

Reported-by: Juha Leppanen <juha_motorsportcom@luukku.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: Janne Ylalehto <janne.ylalehto@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>