In HS2 doAs=false mode, file system related errors in one query causes other failures

Warehouse class has a few methods that close file system object on errors.
With doAs=false, since all queries use the same HS2 ugi, the filesystem object is shared across queries/threads. When the close on one filesystem object gets called, it leads to filesystem object used in other threads also get closed and any files registered for deletion on exit also getting deleted.

There is also no close being done in case of the happy code path.