bcm43xx: Fix for oops on ampdu status

If bcm43xx were to process an afterburner (ampdu) status response, Linux would oops. The
ampdu and intermediate status bits are properly named.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>