*: call if_init()/if_terminate() from vrf_init()/vrf_terminate()

Later, an interface will belong to a specific VRF, and the interface
initialization will be a part of the VRF initialization. So now call
if_init() from vrf_init(), and if_terminate() from vrf_terminate().

Daemons have the according changes:
- if if_init() was called or "iflist" was initialized, now call
  vrf_init() instead;
- if if_terminate() was called or "iflist" was destroyed, now call
  vrf_terminate() instead.

Signed-off-by: Feng Lu <lu.feng@6wind.com>
Reviewed-by: Alain Ritoux <alain.ritoux@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vincent JARDIN <vincent.jardin@6wind.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/ripd/rip_main.c b/ripd/rip_main.c
index e81e61b..95b1f6d 100644
--- a/ripd/rip_main.c
+++ b/ripd/rip_main.c
@@ -33,6 +33,7 @@
 #include "privs.h"
 #include "sigevent.h"
 #include "zclient.h"
+#include "vrf.h"
 
 #include "ripd/ripd.h"
 
@@ -280,6 +281,7 @@
   vty_init (master);
   memory_init ();
   keychain_init ();
+  vrf_init ();
 
   /* RIP related initialization. */
   rip_init ();