perf parse events: Demystify memory allocations

perf parse events: Demystify memory allocations

List heads are currently allocated way down the function chain in
__add_event and add_tracepoint and then freed when the scanner code
calls parse_events_update_lists.

Be more explicit with where memory is allocated and who should free it. With
this patch the list_head is allocated in the scanner code and freed when the
scanner code calls parse_events_update_lists.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1372793245-4136-7-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>