sentry/socket: don't release a connected enpoint under the endpoint mutex

It isn't required and can have side effects. For example, the current endpoint
can be in an SCM message that is queued to the connected endpoint.

PiperOrigin-RevId: 447906621

pkg/sentry/socket/unix/transport/connectionless.go

@@ -59,10 +59,8 @@ func (e *connectionlessEndpoint) isBound() bool {
 // with it.
 func (e *connectionlessEndpoint) Close(ctx context.Context) {
 	e.Lock()
-	if e.connected != nil {
-		e.connected.Release(ctx)
-		e.connected = nil
-	}
+	connected := e.connected
+	e.connected = nil
 
 	if e.isBound() {
 		e.path = ""
@@ -73,6 +71,9 @@ func (e *connectionlessEndpoint) Close(ctx context.Context) {
 	e.receiver = nil
 	e.Unlock()
 
+	if connected != nil {
+		connected.Release(ctx)
+	}
 	r.CloseNotify()
 	r.Release(ctx)
 }