Fixed typo in DirectorySearcher.Asyncronous page (#4057)

Author: ef4203

xml/System.DirectoryServices/DirectorySearcher.xml

@@ -452,7 +452,7 @@ using System.DirectoryServices;
 // Bind to the users container.  
 DirectoryEntry entry = new DirectoryEntry("LDAP://CN=users,DC=fabrikam,DC=com");  
 // Create a DirectorySearcher object.  
-DirectorySearcher mySearcher = new DirectorySearcher(entry);  
+DirectorySearcher src = new DirectorySearcher(entry);  
 //Set the Asynchronous property to true.  
 src.Asynchronous = true;  
 //Use the FindAll method to get search results.