Revert breaking parameter rename

Author: ryanbrandenburg

src/Microsoft.AspNetCore.Authentication.OpenIdConnect/OpenIdConnectHandler.cs

@@ -150,7 +150,7 @@ protected virtual async Task<bool> HandleRemoteSignOutAsync()
  /// Redirect user to the identity provider for sign out
  /// </summary>
  /// <returns>A task executing the sign out procedure</returns>
- protected override async Task HandleSignOutAsync(SignOutContext context)
+ protected override async Task HandleSignOutAsync(SignOutContext signout)
  {
  Logger.EnteringOpenIdAuthenticationHandlerHandleSignOutAsync(GetType().FullName);
 
@@ -168,7 +168,7 @@ protected override async Task HandleSignOutAsync(SignOutContext context)
  };
 
  // Get the post redirect URI.
- var properties = new AuthenticationProperties(context.Properties);
+ var properties = new AuthenticationProperties(signout.Properties);
  if (string.IsNullOrEmpty(properties.RedirectUri))
  {
  properties.RedirectUri = BuildRedirectUriIfRelative(Options.PostLogoutRedirectUri);