Fix class/struct naming (dotnet#9405)

Author: deeprobin

xml/System.Security.Cryptography/CngProperty.xml

@@ -58,9 +58,9 @@
       <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- This class encapsulates a property name (a string), a value (byte array), a <xref:System.Security.Cryptography.CngPropertyOptions> flag, accessor properties, and comparison and hashing functions.  
+ This struct encapsulates a property name (a string), a value (byte array), a <xref:System.Security.Cryptography.CngPropertyOptions> flag, accessor properties, and comparison and hashing functions.  
   
- This class is used with the <xref:System.Security.Cryptography.CngKey.SetProperty%2A> and <xref:System.Security.Cryptography.CngKey.GetProperty%2A> methods.  
+ This struct is used with the <xref:System.Security.Cryptography.CngKey.SetProperty%2A> and <xref:System.Security.Cryptography.CngKey.GetProperty%2A> methods.  
   
  ]]></format>
     </remarks>
@@ -115,7 +115,7 @@
         <param name="name">The property name to initialize.</param>
         <param name="value">The property value to initialize.</param>
         <param name="options">A bitwise combination of the enumeration values that specify how the property is stored.</param>
-        <summary>Initializes a new instance of the <see cref="T:System.Security.Cryptography.CngProperty" /> class.</summary>
+        <summary>Initializes a new instance of the <see cref="T:System.Security.Cryptography.CngProperty" /> struct.</summary>
         <remarks>
           <format type="text/markdown"><![CDATA[