[gnome-desktop] thumbnail: Fix compile-time warning

[Bastien Nocera <hadess src gnome org>]

commit 7c396cf7d7881533a38804bcfe4ce81927d29ee2
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Jan 16 15:54:15 2018 +0100

    thumbnail: Fix compile-time warning
    
    gnome-desktop/libgnome-desktop/gnome-desktop-thumbnail-script.c: In function ‘setup_seccomp’:
    gnome-desktop/libgnome-desktop/gnome-desktop-thumbnail-script.c:431:17: warning: comparison between 
signed and unsigned integer expressions [-Wsign-compare]
       for (i = 0; i < G_N_ELEMENTS (syscall_blacklist); i++)
                     ^

 libgnome-desktop/gnome-desktop-thumbnail-script.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/libgnome-desktop/gnome-desktop-thumbnail-script.c 
b/libgnome-desktop/gnome-desktop-thumbnail-script.c
index 99d83ac..9529b67 100644
--- a/libgnome-desktop/gnome-desktop-thumbnail-script.c
+++ b/libgnome-desktop/gnome-desktop-thumbnail-script.c
@@ -363,7 +363,8 @@ setup_seccomp (GPtrArray  *argv_array,
     AF_KEY,
     AF_NETLINK + 1, /* Last gets CMP_GE, so order is important */
   };
-  int i, r;
+  guint i;
+  int r;
   int fd = -1;
   g_autofree char *fd_str = NULL;
   g_autofree char *path = NULL;