perf tools: Use perf_event_terms__purge() for non-malloced terms

perf tools: Use perf_event_terms__purge() for non-malloced terms

In these two cases, a 'perf test' entry and in the PMU code the
list_head is on the stack, so we can't use perf_event__free_terms()
(soon to be renamed to perf_event_terms__delete()), because it will
free the list_head as well.

Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/tip-i956ryjhz97gnnqe8iqe7m7s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>