Update EventSource+EventData.xml (#8785)

Fixed code sample. There is no type `EventProvider.EventData`

Author: KrzysztofCwalina

xml/System.Diagnostics.Tracing/EventSource+EventData.xml

@@ -51,7 +51,7 @@
   
 [NonEvent]  
 public unsafe void WriteEvent(int eventId, int arg1, int arg2, int arg3, int arg4) {  
-    EventData* dataDesc = stackalloc EventProvider.EventData[4];  
+    EventData* dataDesc = stackalloc EventSource.EventData[4];  
   
     dataDesc[0].DataPointer = (IntPtr)(&arg1);  
     dataDesc[0].Size = 4;