perf kvm powerpc: Fix build

Updates to struct parse_events_error needed to be carried through to
PowerPC specific event parsing.

Fixes: fd7b8e8f ("perf parse-events: Print all errors")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung <namhyung@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240206235902.2917395-1-irogers@google.com

tools/perf/arch/powerpc/util/kvm-stat.c

@@ -114,7 +114,7 @@ static int is_tracepoint_available(const char *str, struct evlist *evlist)
 
 	parse_events_error__init(&err);
 	ret = parse_events(evlist, str, &err);
-	if (err.str)
+	if (ret)
 		parse_events_error__print(&err, "tracepoint");
 	parse_events_error__exit(&err);
 	return ret;