Inline TryMapToRazorDocumentPosition call instead of storing result

Removed the intermediate mappedEnd assignment and directly used the
TryMapToRazorDocumentPosition result in the if condition. This makes
the code cleaner by avoiding the unnecessary variable assignment.

Co-authored-by: davidwengier <[email protected]>

Author: Copilot

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DocumentMapping/AbstractDocumentMappingService.cs

@@ -113,9 +113,7 @@ public IEnumerable<TextChange> GetRazorDocumentEdits(RazorCSharpDocument csharpD
                     break;
                 }
 
-                mappedEnd = this.TryMapToRazorDocumentPosition(csharpDocument, endIndex, out _, out hostEndIndex);
-
-                if (mappedEnd)
+                if (this.TryMapToRazorDocumentPosition(csharpDocument, endIndex, out _, out hostEndIndex))
                 {
                     // If there's a newline in the new text, only take the part before it
                     var firstNewLine = change.NewText.AssumeNotNull().IndexOfAny(['\n', '\r']);