perf data: Move perf_dir_version into data.h

perf_dir_version belongs to struct perf_data which is declared in data.h.
To allow its use in inline perf_data functions, move perf_dir_version to
data.h
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191004083121.12182-3-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/data.h

@@ -9,6 +9,10 @@ enum perf_data_mode {
 	PERF_DATA_MODE_READ,
 };
 
+enum perf_dir_version {
+	PERF_DIR_VERSION	= 1,
+};
+
 struct perf_data_file {
 	char		*path;
 	int		 fd;

tools/perf/util/header.h

@@ -52,10 +52,6 @@ enum perf_header_version {
 	PERF_HEADER_VERSION_2,
 };
 
-enum perf_dir_version {
-	PERF_DIR_VERSION	= 1,
-};
-
 struct perf_file_section {
 	u64 offset;
 	u64 size;