Fix name of parameter in ArgumentNullException (Azure#39803)

Author: JoshLove-msft

sdk/extensions/Azure.Extensions.AspNetCore.Configuration.Secrets/CHANGELOG.md

@@ -16,6 +16,9 @@ Thank you to our developer community members who helped to make the Key Vault co
 
 ### Bugs Fixed
 
+- Corrected the parameter name in the `ArgumentNullException` that is thrown if a null `options` argument is passed 
+  to `AddAzureKeyVault`.
+
 ### Other Changes
 
 ## 1.2.2 (2022-04-05)

sdk/extensions/Azure.Extensions.AspNetCore.Configuration.Secrets/src/AzureKeyVaultConfigurationExtensions.cs

@@ -98,7 +98,7 @@ public static IConfigurationBuilder AddAzureKeyVault(
             AzureKeyVaultConfigurationOptions options)
         {
             Argument.AssertNotNull(configurationBuilder, nameof(configurationBuilder));
-            Argument.AssertNotNull(options, nameof(configurationBuilder));
+            Argument.AssertNotNull(options, nameof(options));
             Argument.AssertNotNull(client, nameof(client));
             Argument.AssertNotNull(options.Manager, $"{nameof(options)}.{nameof(options.Manager)}");