[nautilus] Don't trigger an int overflow on files' age computation

[Carlos Soriano Sánchez <csoriano src gnome org>]

commit e6587b86b4c7543a3b0fd20da88d964865106d86
Author: Sebastien Bacher <seb128 ubuntu com>
Date:   Tue Dec 1 13:41:27 2015 +0100

    Don't trigger an int overflow on files' age computation
    
    https://bugzilla.gnome.org/show_bug.cgi?id=758898

 libnautilus-private/nautilus-file.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/libnautilus-private/nautilus-file.c b/libnautilus-private/nautilus-file.c
index 8fde7c5..811251d 100644
--- a/libnautilus-private/nautilus-file.c
+++ b/libnautilus-private/nautilus-file.c
@@ -4712,8 +4712,7 @@ nautilus_file_get_date_as_string (NautilusFile       *file,
                                                         g_date_time_get_day_of_month (now),
                                                         0, 1, 0);
 
-               days_ago = g_date_time_difference (today_midnight, file_date) /
-                           (24 * 60 * 60 * 1000 * 1000L);
+               days_ago = g_date_time_difference (now, file_date) / G_TIME_SPAN_DAY;
 
                use_24 = g_settings_get_enum (gnome_interface_preferences, "clock-format") ==
                         G_DESKTOP_CLOCK_FORMAT_24H;