staging: rtl8188eu: remove return variable from rtw_pwr_unassociated_idle

staging: rtl8188eu: remove return variable from rtw_pwr_unassociated_idle

Function rtw_pwr_unassociated_idle returns boolean values.
Remove the return variable ret and the exit label to simplify the
function a little bit. Return true or false directly instead.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Link: https://lore.kernel.org/r/20191123151635.155138-3-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>