perf data: Rename directory "header" file to "data"

In preparation to support a single file directory format, rename "header"
to "data" because "header" is a mis-leading name when there is only 1 file.
Note, in the multi-file case, the "header" file also contains data.

Signed-off-by: Adrian Hunter <[e-mail]>
Reviewed-by: Jiri Olsa <[e-mail]>
Link: http://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/data.c

···
 	 * So far we open only the header, so we can read the data version and
 	 * layout.
 	 */
-	if (asprintf(&data->file.path, "%s/header", data->path) < 0)
+	if (asprintf(&data->file.path, "%s/data", data->path) < 0)
 		return -1;
 
 	if (perf_data__is_write(data) &&

tools/perf/util/util.c

···
 int rm_rf_perf_data(const char *path)
 {
 	const char *pat[] = {
-		"header",
+		"data",
 		"data.*",
 		NULL,
 	};