ath10k: fix printing of peer stats in non-AP firmware

This patch is intended to fix the problem if we use the
firmware 999.999.0.636 to get peer stats when the number
of peer is more than 3. The WMI_UPDATE_STATS_EVENTID may
trigger more than 1 time if the number of peers is more
than 3. So this patch allows us to do the checking on this
and make sure that we print the peer stats correctly.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>