Question about FIXME in the function,ath10k_htc_send_complete_check for the file htc.c

Greetings Again Kalle and others,
I am wondering about the fix me in the function,ath10k_htc_send_complete_check for the file,htc.c. I am wondering if there is a hardware limitation and the line for reserving 20 bytes for the sk_buff used is need in this function. I am assuming this is needed due to hardware limitations and therefore can't be removed but should be commented explaining this limitation. Please let me known otherwise if I am missing something.
Thanks,
Nick