util: add an ARRAY_SIZE helper.

Bug: None
Test: `make tests` pass
Change-Id: Iecd2015b7ff96cdd78ff61c905ad065e272c2885
diff --git a/util.c b/util.c
index 58f627b..d91d068 100644
--- a/util.c
+++ b/util.c
@@ -64,7 +64,7 @@
 #error "Unsupported platform"
 #endif
 
-const size_t log_syscalls_len = sizeof(log_syscalls)/sizeof(log_syscalls[0]);
+const size_t log_syscalls_len = ARRAY_SIZE(log_syscalls);
 
 int lookup_syscall(const char *name)
 {