*: get rid of "MTYPE 0"

A few places are using 0 in place of the MTYPE_* argument.  The
following rewrite of the alloc tracking won't deal with that, so let's
use MTYPE_TMP instead.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Acked-by: Donald Sharp <sharpd@cumulusnetworks.com>
diff --git a/vtysh/vtysh_user.c b/vtysh/vtysh_user.c
index 239a633..248b181 100644
--- a/vtysh/vtysh_user.c
+++ b/vtysh/vtysh_user.c
@@ -102,7 +102,7 @@
 static struct vtysh_user *
 user_new ()
 {
-  return XCALLOC (0, sizeof (struct vtysh_user));
+  return XCALLOC (MTYPE_TMP, sizeof (struct vtysh_user));
 }
 
 #if 0