libertas_tf: Use correct channel range in lbtf_geo_init

It seems we should use 'range' instead of 'priv->range'
in lbtf_geo_init(), because 'range' is the corret one
related to current regioncode.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 691cdb49 ("libertas_tf: command helper functions for libertas_tf")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>