ath6kl: remove useless cleanup call from ath6kl_bmi_done()

aht6kl core code will call the cleanup function when the device is removed.
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/bmi.c

@@ -196,8 +196,6 @@ int ath6kl_bmi_done(struct ath6kl *ar)
 		return ret;
 	}
 
-	ath6kl_bmi_cleanup(ar);
-
 	return 0;
 }