[sysprof] libsysprof-ui: fix timing information for marks tooltips

[Christian Hergert <chergert src gnome org>]

commit bae10987f05b32098402c95ab292bb1680460225
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 24 09:29:17 2020 -0800

    libsysprof-ui: fix timing information for marks tooltips

 src/libsysprof-ui/sysprof-marks-page.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/libsysprof-ui/sysprof-marks-page.c b/src/libsysprof-ui/sysprof-marks-page.c
index f6f59a2..7574d55 100644
--- a/src/libsysprof-ui/sysprof-marks-page.c
+++ b/src/libsysprof-ui/sysprof-marks-page.c
@@ -238,14 +238,16 @@ sysprof_marks_page_tree_view_query_tooltip_cb (SysprofMarksPage *self,
           g_autofree gchar *tooltip_text = NULL;
           g_autofree gchar *durationstr = NULL;
           gint64 begin_time;
+          gint64 end_time;
           gint64 duration;
 
           gtk_tree_model_get (model, &iter,
                               SYSPROF_MARKS_MODEL_COLUMN_BEGIN_TIME, &begin_time,
-                              SYSPROF_MARKS_MODEL_COLUMN_DURATION, &duration,
+                              SYSPROF_MARKS_MODEL_COLUMN_END_TIME, &end_time,
                               SYSPROF_MARKS_MODEL_COLUMN_TEXT, &text,
                               -1);
 
+          duration = end_time - begin_time;
           begin_time -= priv->capture_begin_time;
           durationstr = _sysprof_format_duration (duration);