[cleanup] Convert XMALLOC/memset to XCALLOC

Simple conversion of XMALLOC/memset to XCALLOC
diff --git a/ospf6d/ospf6_asbr.c b/ospf6d/ospf6_asbr.c
index 37b912b..685b147 100644
--- a/ospf6d/ospf6_asbr.c
+++ b/ospf6d/ospf6_asbr.c
@@ -504,8 +504,7 @@
   memcpy (&route->prefix, prefix, sizeof (struct prefix));
 
   info = (struct ospf6_external_info *)
-    XMALLOC (MTYPE_OSPF6_EXTERNAL_INFO, sizeof (struct ospf6_external_info));
-  memset (info, 0, sizeof (struct ospf6_external_info));
+    XCALLOC (MTYPE_OSPF6_EXTERNAL_INFO, sizeof (struct ospf6_external_info));
   route->route_option = info;
   info->id = ospf6->external_id++;
 
diff --git a/ospf6d/ospf6_interface.c b/ospf6d/ospf6_interface.c
index 8d9a7f0..4215208 100644
--- a/ospf6d/ospf6_interface.c
+++ b/ospf6d/ospf6_interface.c
@@ -96,11 +96,9 @@
   unsigned int iobuflen;
 
   oi = (struct ospf6_interface *)
-    XMALLOC (MTYPE_OSPF6_IF, sizeof (struct ospf6_interface));
+    XCALLOC (MTYPE_OSPF6_IF, sizeof (struct ospf6_interface));
 
-  if (oi)
-    memset (oi, 0, sizeof (struct ospf6_interface));
-  else
+  if (!oi)
     {
       zlog_err ("Can't malloc ospf6_interface for ifindex %d", ifp->ifindex);
       return (struct ospf6_interface *) NULL;
diff --git a/ospf6d/ospf6_lsa.c b/ospf6d/ospf6_lsa.c
index 87df741..e8290b6 100644
--- a/ospf6d/ospf6_lsa.c
+++ b/ospf6d/ospf6_lsa.c
@@ -468,8 +468,7 @@
   /* LSA information structure */
   /* allocate memory */
   lsa = (struct ospf6_lsa *)
-    XMALLOC (MTYPE_OSPF6_LSA, sizeof (struct ospf6_lsa));
-  memset (lsa, 0, sizeof (struct ospf6_lsa));
+    XCALLOC (MTYPE_OSPF6_LSA, sizeof (struct ospf6_lsa));
 
   lsa->header = (struct ospf6_lsa_header *) new_header;
 
@@ -498,8 +497,7 @@
   /* LSA information structure */
   /* allocate memory */
   lsa = (struct ospf6_lsa *)
-    XMALLOC (MTYPE_OSPF6_LSA, sizeof (struct ospf6_lsa));
-  memset (lsa, 0, sizeof (struct ospf6_lsa));
+    XCALLOC (MTYPE_OSPF6_LSA, sizeof (struct ospf6_lsa));
 
   lsa->header = (struct ospf6_lsa_header *) new_header;
   SET_FLAG (lsa->flag, OSPF6_LSA_HEADERONLY);
diff --git a/ospf6d/ospf6_top.c b/ospf6d/ospf6_top.c
index f59b6f9..d45d132 100644
--- a/ospf6d/ospf6_top.c
+++ b/ospf6d/ospf6_top.c
@@ -114,8 +114,7 @@
 {
   struct ospf6 *o;
 
-  o = XMALLOC (MTYPE_OSPF6_TOP, sizeof (struct ospf6));
-  memset (o, 0, sizeof (struct ospf6));
+  o = XCALLOC (MTYPE_OSPF6_TOP, sizeof (struct ospf6));
 
   /* initialize */
   gettimeofday (&o->starttime, (struct timezone *) NULL);