isisd: address Coverity warnings

this fixes a bunch of issues found by Coverity SCAN and flagged as
"high" impact -- although, they're all rather minute issues.

* isisd/isis_adjacency.c: one superfluous check, one possible NULL deref
* isisd/isis_circuit.c: two prefix memory leaks
* isisd/isis_csm.c: one missing break
* isisd/isis_lsp.c: one possible NULL deref
* isisd/isis_pfpacket.c: one error-case fd leak
* isisd/isis_route.c: one isis_route_info memory leak
* isisd/isis_routemap.c: one... fnord
* isisd/isis_tlv.c: one infinite loop

Reported-by: Coverity SCAN
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/isisd/isis_routemap.c b/isisd/isis_routemap.c
index 558d391..84a14ac 100644
--- a/isisd/isis_routemap.c
+++ b/isisd/isis_routemap.c
@@ -69,8 +69,7 @@
   for (i = 0; i <= ZEBRA_ROUTE_MAX; i++)
     {
       if (isis->rmap[i].name)
-	isis->rmap[i].map = isis->rmap[i].map =
-	  route_map_lookup_by_name (isis->rmap[i].name);
+	isis->rmap[i].map = route_map_lookup_by_name (isis->rmap[i].name);
       else
 	isis->rmap[i].map = NULL;
     }