Allow empty DPDK device init config

This patch allows for empty dpdk device configuration
such as: dpdk { dev 0000:0a:00.0 { } }

Instead of exiting.

Change-Id: If9488eecc7fb1e0b5c6626f9c074649b39b727d3
Signed-off-by: Pierre Pfister <ppfister@cisco.com>
diff --git a/vnet/vnet/devices/dpdk/init.c b/vnet/vnet/devices/dpdk/init.c
index 01bd27d..e06d6bf 100644
--- a/vnet/vnet/devices/dpdk/init.c
+++ b/vnet/vnet/devices/dpdk/init.c
@@ -906,6 +906,7 @@
   if (!input)
     return 0;
 
+  unformat_skip_white_space (input);
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (input, "num-rx-queues %u", &devconf->num_rx_queues))