Fix parameter definition for constructor in EventWaitHandle.xml (#5087)

Author: TianqiZhang

xml/System.Threading/EventWaitHandle.xml

@@ -195,7 +195,7 @@
       <Parameters>
         <Parameter Name="initialState" Type="System.Boolean" />
         <Parameter Name="mode" Type="System.Threading.EventResetMode" />
-        <param name="name">The name, if the synchronization object is to be shared with other processes; otherwise, <see langword="null" /> or an empty string. The name is case-sensitive.</param>
+        <Parameter Name="name" Type="System.String" />
       </Parameters>
       <Docs>
         <param name="initialState">