Fix VPP-1528 get the same IP address from DHCP server for two VPP DHCP clients

Change-Id: I18dfe51000758f44b991d2dd065c9aa2bc5863d5
Signed-off-by: jackiechen1985 <xiaobo.chen@tieto.com>
diff --git a/src/vnet/dhcp/client.c b/src/vnet/dhcp/client.c
index b89b8f2..b571068 100644
--- a/src/vnet/dhcp/client.c
+++ b/src/vnet/dhcp/client.c
@@ -1209,7 +1209,7 @@
 
   dcm->vlib_main = vm;
   dcm->vnet_main = vnet_get_main ();
-  dcm->seed = 0xdeaddabe;
+  dcm->seed = (u32) clib_cpu_time_now ();
   return 0;
 }