*: 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/zebra/test_main.c b/zebra/test_main.c
index 70a1a3a..a951863 100644
--- a/zebra/test_main.c
+++ b/zebra/test_main.c
@@ -280,7 +280,7 @@
   zebrad.master = thread_master_create ();
 
   /* Vty related initialize. */
-  signal_init (zebrad.master, Q_SIGC(zebra_signals), zebra_signals);
+  signal_init (zebrad.master, array_size(zebra_signals), zebra_signals);
   cmd_init (1);
   vty_init (zebrad.master);
   memory_init ();