ospfd: compile warning cleanups

A set of patches to clarify some comments as well as cleanup code that was
causing warnings.  After these patches, the code can be compiled with

-Wall -Wsign-compare -Wpointer-arith -Wbad-function-cast -Wwrite-strings
-Wmissing-prototypes -Wmissing-declarations -Wchar-subscripts -Wcast-qual
-Wextra -Wno-unused-parameter -Wno-missing-field-initializers

(what is current in trunk plus -Wextra -Wno-unused-parameter
-Wno-missing-field-initializers).

Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
diff --git a/ospfd/ospf_zebra.c b/ospfd/ospf_zebra.c
index f5f49f6..34a3b2a 100644
--- a/ospfd/ospf_zebra.c
+++ b/ospfd/ospf_zebra.c
@@ -133,8 +133,8 @@
 
   if (IS_DEBUG_OSPF (zebra, ZEBRA_INTERFACE))
     zlog_debug
-      ("Zebra: interface delete %s index %d flags %lld metric %d mtu %d",
-       ifp->name, ifp->ifindex, ifp->flags, ifp->metric, ifp->mtu);
+      ("Zebra: interface delete %s index %d flags %llx metric %d mtu %d",
+       ifp->name, ifp->ifindex, (unsigned long long)ifp->flags, ifp->metric, ifp->mtu);
 
 #ifdef HAVE_SNMP
   ospf_snmp_if_delete (ifp);
@@ -1004,7 +1004,7 @@
 
 /* Update distribute-list and set timer to apply access-list. */
 void
-ospf_distribute_list_update (struct ospf *ospf, int type)
+ospf_distribute_list_update (struct ospf *ospf, uintptr_t type)
 {
   struct route_table *rt;
 
@@ -1217,7 +1217,6 @@
 {
   int ret;
   struct prefix_ipv4 p;
-  u_char distance;
   struct route_node *rn;
   struct ospf_distance *odistance;
 
@@ -1228,8 +1227,6 @@
       return CMD_WARNING;
     }
 
-  distance = atoi (distance_str);
-
   rn = route_node_lookup (ospf->distance_table, (struct prefix *) &p);
   if (!rn)
     {