i#5675: Fix data race in record_filter.

[abhinav92003]

Fixes a race in updating input_entry_count_ and output_entry_count_
in parallel_shard_exit in the record_filter analyzer.

Moves aggregation logic to print_results instead. Like other analyzers,
we now keep track of all shard data pointers and free them in the
destructor instead. We destroy the writer object in parallel_shard_exit
itself though, for symmetry with how it's created (in parallel_shard_stream_init)
and so that users don't have to destroy the record_filter_t object itself
for output files to be written out.

Issue: #5675

[abhinav92003]

Created #5774 for the AArch64 failure. It's definitely unrelated to this PR.