error-report: make real_time_iso8601() public

To be reused in the following commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20260201173633.413934-3-vsementsov@yandex-team.ru>

include/qemu/error-report.h

@@ -74,4 +74,10 @@ extern bool message_with_timestamp;
 extern bool error_with_guestname;
 extern const char *error_guest_name;
 
+/*
+ * Return current datetime in ISO 8601 format.
+ * Caller is responsible to g_free() the returned string.
+ */
+char *real_time_iso8601(void);
+
 #endif

util/error-report.c

@@ -169,8 +169,7 @@ static void print_loc(void)
     }
 }
 
-static char *
-real_time_iso8601(void)
+char *real_time_iso8601(void)
 {
     g_autoptr(GDateTime) dt = g_date_time_new_now_utc();
     return g_date_time_format_iso8601(dt);