device: fix nil pointer dereference in uapi read

Signed-off-by: David Anderson <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

device/uapi.go

@@ -258,11 +258,11 @@ type ipcSetPeer struct {
 }
 
 func (peer *ipcSetPeer) handlePostConfig() {
-	if peer.Peer == nil {
+	if peer.Peer == nil || peer.dummy {
 		return
 	}
 	peer.disableRoaming = peer.device.net.brokenRoaming && peer.endpoint != nil
-	if !peer.dummy && peer.device.isUp() {
+	if peer.device.isUp() {
 		peer.Start()
 		if peer.pkaOn {
 			peer.SendKeepalive()