usb/dev-mtp: use GDateTime for formatting timestamp for objects

The GDateTime APIs provided by GLib avoid portability pitfalls, such
as some platforms where 'struct timeval.tv_sec' field is still 'long'
instead of 'time_t'. When combined with automatic cleanup, GDateTime
often results in simpler code too.

Reviewed-by: Gerd Hoffmann <[email protected]>
Signed-off-by: Daniel P. Berrangé <[email protected]>

Author: berrange

hw/usb/dev-mtp.c

@@ -772,12 +772,9 @@ static void usb_mtp_add_str(MTPData *data, const char *str)
 
 static void usb_mtp_add_time(MTPData *data, time_t time)
 {
-    char buf[16];
-    struct tm tm;
-
-    gmtime_r(&time, &tm);
-    strftime(buf, sizeof(buf), "%Y%m%dT%H%M%S", &tm);
-    usb_mtp_add_str(data, buf);
+    g_autoptr(GDateTime) then = g_date_time_new_from_unix_utc(time);
+    g_autofree char *thenstr = g_date_time_format(then, "%Y%m%dT%H%M%S");
+    usb_mtp_add_str(data, thenstr);
 }
 
 /* ----------------------------------------------------------------------- */