lib/vsprintf: do not show no_hash_pointers message multiple times

Do not show no_hash_pointers message multiple times if the option was
passed more than once (e.g. via generated command line).
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210305194206.3165917-1-elver@google.com

lib/vsprintf.c

@@ -2096,6 +2096,9 @@ EXPORT_SYMBOL_GPL(no_hash_pointers);
 
 static int __init no_hash_pointers_enable(char *str)
 {
+	if (no_hash_pointers)
+		return 0;
+
 	no_hash_pointers = true;
 
 	pr_warn("**********************************************************\n");