qcacld-3.0: Fix bad numPeers reference

The following patch replaced typedef tSirWifiPeerStat with a new
struct wifi_peer_stat that has member names that following the Linux
coding style:
  qcacld-3.0: Replace typedef tSirWifiPeerStat
  Change-Id I337e2329d544e0b6daf6650f826e736f2492ef30

As part of that change all instances of tSirWifiPeerStat::numPeers
should have been replaced with wifi_peer_stat::num_peers, but one
instance was overlooked in wma_peer_ps_evt_handler(), so fix it now.

Note that ideally the compiler should have caught this, but
wma_peer_ps_evt_handler() is conditionally compiled, and apparently
the WLAN_PEER_PS_NOTIFICATION feature is not enabled on any current
targets.

Change-Id: If7fc2d38886119f2e21413213ad386d2ad19e4f3
CRs-Fixed: 3431813

core/wma/src/wma_utils.c

@@ -2513,7 +2513,7 @@ static int wma_peer_ps_evt_handler(void *handle, u_int8_t *event,
 	link_stats_results->moreResultToFollow = 0;
 
 	peer_stat = (struct wifi_peer_stat *)link_stats_results->results;
-	peer_stat->numPeers = 1;
+	peer_stat->num_peers = 1;
 	peer_info = (struct wifi_peer_info *)peer_stat->peer_info;
 	qdf_mem_copy(&peer_info->peer_macaddr,
 		     &mac_address,