clang-tidy: add ending namespace comments

Found with google-readability-namespace-comments

Signed-off-by: Rosen Penev <[email protected]>

taglib/xm/xmfile.h

@@ -106,7 +106,7 @@ namespace TagLib {
         class FilePrivate;
         FilePrivate *d;
     };
-  }
-}
+  }  // namespace XM
+}  // namespace TagLib
 
 #endif

taglib/xm/xmproperties.h

@@ -79,7 +79,7 @@ namespace TagLib {
       class PropertiesPrivate;
       PropertiesPrivate *d;
     };
-  }
-}
+  }  // namespace XM
+}  // namespace TagLib
 
 #endif