perf BPF related improvements and bugfix:

 - Call bpf__clear() in command 'record, top, stat and trace' to ensure
   release BPF related resources.

 - Correct --filter option when try to apply filter to BPF object.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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=/2L1
-----END PGP SIGNATURE-----