Simplify syntax checks by using Parent instead of GetPreviousToken

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers/LayoutRules/SA1500BracesForMultiLineStatementsMustNotShareLine.cs

@@ -290,9 +290,8 @@ private static void CheckBraceToken(SyntaxNodeAnalysisContext context, SyntaxTok
                     // may want to allow that and not have SA1500 report it as a style error.
                     if (context.GetStyleCopSettings(context.CancellationToken).LayoutRules.AllowDoWhileOnClosingBrace)
                     {
-                        var openBracePreviousToken = openBraceToken.GetPreviousToken(includeZeroWidth: true);
-
-                        if (openBracePreviousToken.IsKind(SyntaxKind.DoKeyword))
+                        if (openBraceToken.Parent.IsKind(SyntaxKind.Block)
+                            && openBraceToken.Parent.Parent.IsKind(SyntaxKind.DoStatement))
                         {
                             return;
                         }