[ospfd] Fix a few LSA performance "bugs"

ospf_lsa_install() will calculate LSA checksum so no
need to do it before calling ospf_lsa_install().

Set the OSPF_LSA_SELF_CHECKED flag on own LSA's to
save ospf_lsa_is_self_originated() some work.

Do not memset() memory that is about to overwritten
with memcpy().
diff --git a/ospfd/ospf_lsa.c b/ospfd/ospf_lsa.c
index 3c9c73a..18eed79 100644
--- a/ospfd/ospf_lsa.c
+++ b/ospfd/ospf_lsa.c
@@ -201,7 +201,6 @@
   struct ospf_lsa *new;
 
   new = XCALLOC (MTYPE_OSPF_LSA, sizeof (struct ospf_lsa));
-  memset (new, 0, sizeof (struct ospf_lsa));
 
   new->flags = 0;
   new->lock = 1;
@@ -822,7 +821,7 @@
     }
   
   new->area = area;
-  SET_FLAG (new->flags, OSPF_LSA_SELF);
+  SET_FLAG (new->flags, OSPF_LSA_SELF | OSPF_LSA_SELF_CHECKED);
 
   /* Copy LSA data to store, discard stream. */
   new->data = ospf_lsa_data_new (length);
@@ -1081,7 +1080,7 @@
     }
   
   new->area = oi->area;
-  SET_FLAG (new->flags, OSPF_LSA_SELF);
+  SET_FLAG (new->flags, OSPF_LSA_SELF | OSPF_LSA_SELF_CHECKED);
 
   /* Copy LSA to store. */
   new->data = ospf_lsa_data_new (length);
@@ -1275,7 +1274,7 @@
   /* Create OSPF LSA instance. */
   new = ospf_lsa_new ();
   new->area = area;
-  SET_FLAG (new->flags, OSPF_LSA_SELF);
+  SET_FLAG (new->flags, OSPF_LSA_SELF | OSPF_LSA_SELF_CHECKED);
 
   /* Copy LSA to store. */
   new->data = ospf_lsa_data_new (length);
@@ -1346,9 +1345,6 @@
     return NULL;
   
   new->data->ls_seqnum = lsa_seqnum_increment (lsa);
-  
-  /* Re-calculate checksum. */
-  ospf_lsa_checksum (new->data);
 
   ospf_lsa_install (ospf, NULL, new);
   
@@ -1424,7 +1420,7 @@
   /* Create OSPF LSA instance. */
   new = ospf_lsa_new ();
   new->area = area;
-  SET_FLAG (new->flags, OSPF_LSA_SELF);
+  SET_FLAG (new->flags, OSPF_LSA_SELF | OSPF_LSA_SELF_CHECKED);
 
   /* Copy LSA to store. */
   new->data = ospf_lsa_data_new (length);
@@ -1495,9 +1491,6 @@
     return NULL;
   
   new->data->ls_seqnum = lsa_seqnum_increment (lsa);
-  
-  /* Re-calculate checksum. */
-  ospf_lsa_checksum (new->data);
 
   ospf_lsa_install (ospf, NULL, new);
   
@@ -1724,7 +1717,7 @@
   /* Now, create OSPF LSA instance. */
   new = ospf_lsa_new ();
   new->area = NULL;
-  SET_FLAG (new->flags, OSPF_LSA_SELF|OSPF_LSA_APPROVED);
+  SET_FLAG (new->flags, OSPF_LSA_SELF | OSPF_LSA_APPROVED | OSPF_LSA_SELF_CHECKED);
 
   /* Copy LSA data to store, discard stream. */
   new->data = ospf_lsa_data_new (length);
@@ -1811,8 +1804,6 @@
 	    return;
 	  }
 	}
-      /* Re-calculate checksum. */
-      ospf_lsa_checksum (new->data);
 
       /* install also as Type-7 */
       ospf_lsa_install (ospf, NULL, new);   /* Remove Old, Lock New = 2 */
@@ -1862,7 +1853,6 @@
 
   /* add translated flag, checksum and lock new lsa */
   SET_FLAG (new->flags, OSPF_LSA_LOCAL_XLT); /* Translated from 7  */   
-  ospf_lsa_checksum (new->data);
   new = ospf_lsa_lock (new);
   
   return new; 
@@ -2416,9 +2406,6 @@
   
   new->data->ls_seqnum = lsa_seqnum_increment (lsa);
 
-  /* Re-calculate checksum. */
-  ospf_lsa_checksum (new->data);
-
   ospf_lsa_install (ospf, NULL, new);	/* As type-5. */
 
   /* Flood LSA through AS. */