netlink: ensure size_t portability in DEBUG() statement

This prevents the following error when building on 32bit systems with
gcc 4.7.2:

netlink.c: In function 'ir_read':
netlink.c:783:7: error: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'size_t' [-Werror=format]

diff --git a/src/netlink.c b/src/netlink.c
index 422dc8c..3c4642c 100644 (file)
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -683,7 +683,7 @@ static int ir_read (void)
         continue;
       }
 
-      DEBUG ("netlink plugin: ir_read: querying %s from %s (%lu).",
+      DEBUG ("netlink plugin: ir_read: querying %s from %s (%zu).",
           type_name[type_index], iflist[ifindex], ifindex);
 
       nlh = mnl_nlmsg_put_header (buf);