ath11k: use true,false for bool variables

Fix the following coccicheck warning:

drivers/net/wireless/ath/ath11k/dp_rx.c:2964:1-39: WARNING: Assignment
of 0/1 to bool variable
drivers/net/wireless/ath/ath11k/dp_rx.c:2965:1-38: WARNING: Assignment
of 0/1 to bool variable

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200504113336.41249-1-yanaijie@huawei.com