rtlwifi: rtl8192{ce,cu,se} Remove irq_enabled

This should be unnecessary if synchronize_irq is used.

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>