rtlwifi: Remove set_rfpowerstate_inprogress

set_rfpowerstate_inprogress is only set and never read
so remove it.

Signed-off-by: Mike McCormack <mikem@ring3k.org>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>