Update IPnPDevice.cs

Author: nefarius

src/PnP/IPnPDevice.cs

@@ -73,7 +73,7 @@ public interface IPnPDevice
     /// </remarks>
     /// <param name="excludeIfMatches">Returns false if the given predicate is true.</param>
     /// <returns>True if this device originates from an emulator, false otherwise.</returns>
-    bool IsVirtual(Func<IPnPDevice, bool>? excludeIfMatches = default);
+    bool IsVirtual(Func<IPnPDevice, bool>? excludeIfMatches = null);
 
     /// <summary>
     ///     Installs the NULL-driver on this device instance.