example: change key type of xdp example

Signed-off-by: chenqiming <[email protected]>

examples/xdp/main.go

@@ -12,12 +12,12 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"net/netip"
 	"os"
 	"strings"
 	"time"
 
 	"github.com/cilium/ebpf"
-	"github.com/cilium/ebpf/internal"
 	"github.com/cilium/ebpf/link"
 )
 
@@ -71,14 +71,12 @@ func main() {
 func formatMapContents(m *ebpf.Map) (string, error) {
 	var (
 		sb  strings.Builder
-		key uint32
+		key netip.Addr
 		val uint32
 	)
 	iter := m.Iterate()
 	for iter.Next(&key, &val) {
-		b := make([]byte, 4)
-		internal.NativeEndian.PutUint32(b, key)
-		sourceIP := net.IP(b) // IPv4 source address in network byte order.
+		sourceIP := key // IPv4 source address in network byte order.
 		packetCount := val
 		sb.WriteString(fmt.Sprintf("\t%s => %d\n", sourceIP, packetCount))
 	}