constify log syscalls

Bug: None
Test: `make check` passes
Change-Id: Ia306b8bc33f672d9aea658cba219c20ef2197112
diff --git a/util.h b/util.h
index 230bb62..43dccb0 100644
--- a/util.h
+++ b/util.h
@@ -140,7 +140,7 @@
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 /* clang-format on */
 
-extern const char *log_syscalls[];
+extern const char *const log_syscalls[];
 extern const size_t log_syscalls_len;
 
 enum logging_system_t {