*: use array_size() helper macro

Use the array_size() helper macro.  Replaces several instances of local
macros with the same definition.

Reviewed-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/ospf6d/ospf6_main.c b/ospf6d/ospf6_main.c
index d3ef0a6..1bdf52f 100644
--- a/ospf6d/ospf6_main.c
+++ b/ospf6d/ospf6_main.c
@@ -308,7 +308,7 @@
                            LOG_DAEMON);
   zprivs_init (&ospf6d_privs);
   /* initialize zebra libraries */
-  signal_init (master, Q_SIGC(ospf6_signals), ospf6_signals);
+  signal_init (master, array_size(ospf6_signals), ospf6_signals);
   cmd_init (1);
   vty_init (master);
   memory_init ();