rtlwifi: btcoex: 23b 1ant: initialize bt_disabled to false

We only want to disable this if bt_disable_cnt is >= 2.

Fixes: f66509e3 ("rtlwifi: btcoex: Remove 23b 1ant configuration parameter")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>