*: 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/zebra/zserv.c b/zebra/zserv.c
index e0e32ab..c0f9a90 100644
--- a/zebra/zserv.c
+++ b/zebra/zserv.c
@@ -1313,7 +1313,7 @@
   struct zserv *client;
   int i;
 
-  client = XCALLOC (0, sizeof (struct zserv));
+  client = XCALLOC (MTYPE_TMP, sizeof (struct zserv));
 
   /* Make client input/output buffer. */
   client->sock = sock;