Staging: w35und: remove ->adapter from struct _HW_DATA_T

Eventually we want to pass a pointer to struct ieee80211_hw around in the
driver, so remove the bidirectional link between struct wb35_adapter and struct
_HW_DATA_T to simplify the code.

Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>