ath10k: fix the peer mac address in getting stats

Using the macro to convert the MAC address from WMI word
format to char array has lead to the wrong peer mac
address printed out while retrieving the peer stats from
FW. Fix this.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Reviewed-By: Michał Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>