as cached_block::data - which led to a crash as block_cache::FreeBlock() tried to
free both later.
Since neither cached_block::parent_data nor cached_block::original are supposed
to be != NULL in block_cache::FreeBlock(), they are no longer freed, but the system
panics if one of them is not NULL.
This should fix bug #77.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15749 a95241bf-73f2-0310-859d-f6bbb57e9c96