Update src/Features/Core/Portable/ConflictMarkerResolution/AbstractConflictMarkerCodeFixProvider.cs

Co-Authored-By: NSam Harwell <sam@tunnelvisionlabs.com>

src/Features/Core/Portable/ConflictMarkerResolution/AbstractConflictMarkerCodeFixProvider.cs

@@ -107,7 +107,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                 token = token.GetNextToken(includeZeroWidth: true);
                 if (token.RawKind == 0)
                 {
-                    return default;
+                    return null;
                 }
             }
         }