CVE-2023-53802

In the Linux kernel, the following vulnerability has been resolved:

wifi: ath9k: htc_hst: free skb in ath9k_htc_rx_msg() if there is no callback function

It is stated that ath9k_htc_rx_msg() either frees the provided skb or
passes its management to another callback function. However, the skb is
not freed in case there is no another callback function, and Syzkaller was
able to cause a memory leak. Also minor comment fix.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.