Clang: Make it more clear that the FilePathId.filePathId is not shared

The name fileNameId could imply that the id shared for the same file name
which is not the case.

Change-Id: I27310a8994c2d9e9bb0f0aed2094bd988309c710
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/tools/clangrefactoringbackend/source/symbolstorage.h

@@ -86,7 +86,7 @@ public:
             statement.write(locationsEntry.symbolId,
                             locationsEntry.line,
                             locationsEntry.column,
-                            locationsEntry.filePathId.fileNameId);
+                            locationsEntry.filePathId.filePathId);
         }
     }