add test for adapter not found

tests/adapter_tests.rs

@@ -130,3 +130,14 @@ async fn vcan_bulk_send_fd() {
         .send(&Frame::new(0, 0x123.into(), &[0u8; 64]).unwrap())
         .await;
 }
+
+#[tokio::test]
+#[serial_test::serial]
+async fn socketcan_open_nonexistent() {
+    let e = automotive::socketcan::SocketCan::new("doestnotexist");
+
+    match e {
+        Err(automotive::Error::NotFound) => {}
+        _ => panic!("Expected NotFound error"),
+    }
+}