qcacld-3.0: Pointer dereference and resource leak issue fix

Add changes to fix issues:
1. Read from pointer after free
2. Dereference before null check
3. Resource leak

Change-Id: Ie1b18abaa99e9ea168ded897e3f3e9c4cf33fb59
CRs-Fixed: 3295237

os_if/dp/src/os_if_dp.c

@@ -1069,6 +1069,13 @@ int osif_dp_get_nud_stats(struct wiphy *wiphy,
 		goto exit;
 	}
 
+	arp_stats = ucfg_dp_get_arp_stats(vdev);
+	if (!arp_stats) {
+		dp_err("Unable to get ARP stats");
+		err = -EINVAL;
+		goto exit;
+	}
+
 	skb = cfg80211_vendor_cmd_alloc_reply_skb(wiphy,
 						  WLAN_NUD_STATS_LEN);
 	if (!skb) {
@@ -1076,12 +1083,6 @@ int osif_dp_get_nud_stats(struct wiphy *wiphy,
 		err = -ENOMEM;
 		goto exit;
 	}
-	arp_stats = ucfg_dp_get_arp_stats(vdev);
-	if (!arp_stats) {
-		dp_err("Unable to get ARP stats");
-		err = -EINVAL;
-		goto exit;
-	}
 
 	if (nla_put_u16(skb, COUNT_FROM_NETDEV,
 			arp_stats->tx_arp_req_count) ||