refactor: move evdev.linux.sys to evdev.util

Author: MunifTanjim

evdev/linux/sys/init.lua evdev/util.luaevdev/linux/sys/init.lua renamed to evdev/util.lua

@@ -1,15 +1,15 @@
 local ffi = require("ffi")
 
-local function octal(s)
-  return tonumber(s, 8)
-end
-
 ffi.cdef([[
 int printf(const char *__restrict __format, ...);
 int open(const char *__file, int __oflag, ...);
 extern char *strerror (int __errnum);
 ]])
 
+local function octal(s)
+  return tonumber(s, 8)
+end
+
 local mod = {
   O_RDONLY = octal("0000"),
   O_WRONLY = octal("0001"),