clang-tidy: add ending namespace comments

Found with google-readability-namespace-comments

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

taglib/mpc/mpcfile.cpp

@@ -41,7 +41,7 @@ using namespace TagLib;
 namespace
 {
   enum { MPCAPEIndex = 0, MPCID3v1Index = 1 };
-}
+} // namespace
 
 class MPC::File::FilePrivate
 {

taglib/mpc/mpcfile.h

@@ -232,7 +232,7 @@ namespace TagLib {
       class FilePrivate;
       FilePrivate *d;
     };
-  }
-}
+  }  // namespace MPC
+}  // namespace TagLib
 
 #endif

taglib/mpc/mpcproperties.h

@@ -152,7 +152,7 @@ namespace TagLib {
       class PropertiesPrivate;
       PropertiesPrivate *d;
     };
-  }
-}
+  }  // namespace MPC
+}  // namespace TagLib
 
 #endif