Related to #45157
Fix a bug where DataNode panics when building json stats index throws an
exception before the writer is initialized. The destructor would call
Close() on an uninitialized packed_writer_ pointer, causing a null
pointer dereference.
Changes:
- Add null check for packed_writer_ before calling Flush() and Close()
- Prevents null pointer dereference in edge cases
- Ignore close status as this is a cleanup operation
This ensures safe cleanup even when initialization fails due to
exceptions.
Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>
22098c1785