I try to use the command printk.

All the examples I can find on the internet is by putting a string directly in the printk like this:

```
printk(KERN_INFO "Hello %s!", "World");

```

However, I tried to replace the "Hello %s!" using a buffer like this:

```
char buf[] = "Hello %s!";
printk(KERN_INFO buf, "WORLD");

```

It turns out that I get the error

```
error: expected ')' before 'buf'

```

What should we do to using a variable in printk and also use a log level KERN\_INFO?