perf tools: Do not pass NULL to parse_events()

Many cases do not use the extra error information provided by
parse_events and instead pass NULL as the struct parse_events_error
pointer. Add a wrapper for those cases so that the pointer is never
NULL.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220809080702.6921-4-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>