Use new bpf_map__lookup_elem()

Signed-off-by: grantseltzer <grantseltzer@gmail.com>

libbpfgo.go

@@ -646,7 +646,7 @@ func (b *BPFMap) GetValue(key unsafe.Pointer) ([]byte, error) {
 // number of CPUs
 func (b *BPFMap) GetValueReadInto(key unsafe.Pointer, value *[]byte) error {
 	valuePtr := unsafe.Pointer(&(*value)[0])
-	errC := C.bpf_map_lookup_elem(b.fd, key, valuePtr)
+	errC := C.bpf_map__lookup_elem(b.bpfMap, key, C.ulong(b.KeySize()), valuePtr, C.ulong(len(*value)), 0)
 	if errC != 0 {
 		return fmt.Errorf("failed to lookup value %v in map %s: %w", key, b.name, syscall.Errno(-errC))
 	}