Remove outdated blockstorage namespace todo

TODO doesn't really make sense. It would turn some public global
variables into private global variables, but really they shouldn't be
global variables at all. They should be block manager member variables
or chainstate manager member variables.

TODO was added by MarcoFalke <falke.marco@gmail.com> in
fa247a3 in bitcoin#21727 and noticed by Samuel
Dobson <dobsonsa68@gmail.com>
bitcoin#23497 (comment)

src/node/blockstorage.cpp

@@ -27,7 +27,6 @@ bool fHavePruned = false;
 bool fPruneMode = false;
 uint64_t nPruneTarget = 0;
 
-// TODO make namespace {
 RecursiveMutex cs_LastBlockFile;
 std::vector<CBlockFileInfo> vinfoBlockFile;
 int nLastBlockFile = 0;
@@ -42,7 +41,6 @@ std::set<CBlockIndex*> setDirtyBlockIndex;
 
 /** Dirty block file entries. */
 std::set<int> setDirtyFileInfo;
-// } // namespace
 
 static FILE* OpenUndoFile(const FlatFilePos& pos, bool fReadOnly = false);
 static FlatFileSeq BlockFileSeq();