[nautilus] Use helper function to determine if file is root

[William Jon McCann <mccann src gnome org>]

commit d85be64ecf7487c071dd20329584b8ce6a22d470
Author: William Jon McCann <jmccann redhat com>
Date:   Tue Sep 25 12:53:25 2012 -0400

    Use helper function to determine if file is root
    
    https://bugzilla.gnome.org/show_bug.cgi?id=684354

 src/nautilus-properties-window.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)
---
diff --git a/src/nautilus-properties-window.c b/src/nautilus-properties-window.c
index 73e7852..076c9ae 100644
--- a/src/nautilus-properties-window.c
+++ b/src/nautilus-properties-window.c
@@ -2615,7 +2615,6 @@ static gboolean
 should_show_volume_usage (NautilusPropertiesWindow *window)
 {
 	NautilusFile *file;
-	GFile *location;
 	gboolean success = FALSE;
 
 	if (is_multi_file_window (window)) {
@@ -2632,9 +2631,7 @@ should_show_volume_usage (NautilusPropertiesWindow *window)
 		return TRUE;
 	}
 
-	location = nautilus_file_get_location (file);
-	success = nautilus_is_root_directory (location);
-	g_object_unref (location);
+	success = is_root_directory (file);
 
 #ifdef TODO_GIO
 	/* Look at is_mountpoint for activation uri */