CLEANUP: vars: move the per-process variables initialization to vars.c

There's no point keeping the vars_init_head() call in init() when we
already have a vars_init() registered at the right time to do that,
and it complexifies the boot sequence, so let's move it there.

src/haproxy.c

@@ -1540,9 +1540,6 @@ static void init(int argc, char **argv)
 	/* Initialise lua. */
 	hlua_init();
 
-	/* Initialize process vars */
-	vars_init_head(&proc_vars, SCOPE_PROC);
-
 	global.tune.options |= GTUNE_USE_SELECT;  /* select() is always available */
 #if defined(USE_POLL)
 	global.tune.options |= GTUNE_USE_POLL;

src/vars.c

@@ -1335,6 +1335,8 @@ static int vars_max_size_check(char **args, int section_type, struct proxy *curp
 static void vars_init()
 {
 	var_name_hash_seed = ha_random64();
+	/* Initialize process vars */
+	vars_init_head(&proc_vars, SCOPE_PROC);
 }
 
 INITCALL0(STG_PREPARE, vars_init);