[cleanup] Convert XMALLOC/memset to XCALLOC

Simple conversion of XMALLOC/memset to XCALLOC
diff --git a/ospfd/ospf_apiserver.c b/ospfd/ospf_apiserver.c
index dac4c93..15fd2e5 100644
--- a/ospfd/ospf_apiserver.c
+++ b/ospfd/ospf_apiserver.c
@@ -937,8 +937,7 @@
      type. */
 
   regtype =
-    XMALLOC (MTYPE_OSPF_APISERVER, sizeof (struct registered_opaque_type));
-  memset (regtype, 0, sizeof (struct registered_opaque_type));
+    XCALLOC (MTYPE_OSPF_APISERVER, sizeof (struct registered_opaque_type));
   regtype->lsa_type = lsa_type;
   regtype->opaque_type = opaque_type;