perf evswitch: Move enoent error message printing to separate function

Allows adding hints there, will be done in followup patch.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: William Cohen <wcohen@redhat.com>
Link: https://lkml.kernel.org/n/tip-1kvrdi7weuz3hxycwvarcu6v@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evswitch.c

@@ -31,12 +31,17 @@ bool evswitch__discard(struct evswitch *evswitch, struct evsel *evsel)
 	return false;
 }
 
+static int evswitch__fprintf_enoent(FILE *fp, const char *evtype, const char *evname)
+{
+	return fprintf(fp, "ERROR: switch-%s event not found (%s)\n", evtype, evname);
+}
+
 int evswitch__init(struct evswitch *evswitch, struct evlist *evlist, FILE *fp)
 {
 	if (evswitch->on_name) {
 		evswitch->on = perf_evlist__find_evsel_by_str(evlist, evswitch->on_name);
 		if (evswitch->on == NULL) {
-			fprintf(fp, "switch-on event not found (%s)\n", evswitch->on_name);
+			evswitch__fprintf_enoent(fp, "on", evswitch->on_name);
 			return -ENOENT;
 		}
 		evswitch->discarding = true;
@@ -45,7 +50,7 @@ int evswitch__init(struct evswitch *evswitch, struct evlist *evlist, FILE *fp)
 	if (evswitch->off_name) {
 		evswitch->off = perf_evlist__find_evsel_by_str(evlist, evswitch->off_name);
 		if (evswitch->off == NULL) {
-			fprintf(fp, "switch-off event not found (%s)\n", evswitch->off_name);
+			evswitch__fprintf_enoent(fp, "off", evswitch->off_name);
 			return -ENOENT;
 		}
 	}