perf header: In pipe mode dump features without --header/-I

In pipe mode the header features are contained within events. While
other events dump details the header features only dump if --header or
-I are passed, which doesn't make sense as in pipe mode there is no
perf file header. Make the printing of the information conditional on
dump_trace as with other events.

Before:
```
$ perf record -o - -a sleep 1 | perf script -D -i -
...
0x2c8@pipe [0x54]: event: 80
.
. ... raw event: size 84 bytes
.  0000:  50 00 00 00 00 00 54 00 05 00 00 00 00 00 00 00  P.....T.........
.  0010:  40 00 00 00 36 2e 31 35 2e 72 63 37 2e 67 61 64  @...6.15.rc7.gad
.  0020:  32 61 36 39 31 63 39 39 66 62 00 00 00 00 00 00  2a691c99fb......
.  0030:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
.  0040:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
.  0050:  00 00 00 00                                      ....

0 0 0x2c8 [0x54]: PERF_RECORD_FEATURE
```

After:
```
$ perf record -o - -a sleep 1 | perf script -D -i -
...
0x2c8@pipe [0x54]: event: 80
.
. ... raw event: size 84 bytes
.  0000:  50 00 00 00 00 00 54 00 05 00 00 00 00 00 00 00  P.....T.........
.  0010:  40 00 00 00 36 2e 31 35 2e 72 63 37 2e 67 61 64  @...6.15.rc7.gad
.  0020:  32 61 36 39 31 63 39 39 66 62 00 00 00 00 00 00  2a691c99fb......
.  0030:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
.  0040:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
.  0050:  00 00 00 00                                      ....

0 0 0x2c8 [0x54]: PERF_RECORD_FEATURE, # perf version : 6.15.rc7.gad2a691c99fb
```

Signed-off-by: Ian Rogers <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

Author: captain5050

tools/perf/util/header.c

@@ -4326,7 +4326,6 @@ int perf_session__read_header(struct perf_session *session)
 int perf_event__process_feature(struct perf_session *session,
 				union perf_event *event)
 {
-	const struct perf_tool *tool = session->tool;
 	struct feat_fd ff = { .fd = 0 };
 	struct perf_record_header_feature *fe = (struct perf_record_header_feature *)event;
 	int type = fe->header.type;
@@ -4342,28 +4341,23 @@ int perf_event__process_feature(struct perf_session *session,
 		return -1;
 	}
 
-	if (!feat_ops[feat].process)
-		return 0;
-
 	ff.buf  = (void *)fe->data;
 	ff.size = event->header.size - sizeof(*fe);
 	ff.ph = &session->header;
 
-	if (feat_ops[feat].process(&ff, NULL)) {
+	if (feat_ops[feat].process && feat_ops[feat].process(&ff, NULL)) {
 		ret = -1;
 		goto out;
 	}
 
-	if (!feat_ops[feat].print || !tool->show_feat_hdr)
-		goto out;
-
-	if (!feat_ops[feat].full_only ||
-	    tool->show_feat_hdr >= SHOW_FEAT_HEADER_FULL_INFO) {
-		feat_ops[feat].print(&ff, stdout);
-	} else {
-		fprintf(stdout, "# %s info available, use -I to display\n",
-			feat_ops[feat].name);
+	if (dump_trace) {
+		printf(", ");
+		if (feat_ops[feat].print)
+			feat_ops[feat].print(&ff, stdout);
+		else
+			printf("# %s", feat_ops[feat].name);
 	}
+
 out:
 	free_event_desc(ff.events);
 	return ret;