fix parent pointer bug

git-svn-id: https://profuse.googlecode.com/svn/branches/v2@353 aa027e90-d47c-11dd-86d7-074df07e0730

Cache/ConcreteBlockCache.cpp

@@ -61,6 +61,7 @@ using ProFUSE::POSIXException;
 BlockCachePointer ConcreteBlockCache::Create(BlockDevicePointer device, unsigned size)
 {
     //return BlockCachePointer(new ConcreteBlockCache(device, size));
+    // constructor must be accessible to std::make_shared...
     
     return MAKE_SHARED(ConcreteBlockCache, device, size);
 }