[PATCH] libertas: change debug output of libertas_interrupt()

It used to be LBS_DEB_MAIN, now it's LBS_DEB_THREAD

Also fixed a missing ":" in lbs_deb_enter()

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>