[RFC PATCH 1/9] kernel.h: add do_empty() macro

[Joe Perches]

On Sat, 2020-04-18 at 11:41 -0700, Randy Dunlap wrote:
> Add the do_empty() macro to silence gcc warnings about an empty body
> following an "if" statement when -Wextra is used.
> 
> However, for debug printk calls that are being disabled, use either
> no_printk() or pr_debug() [and optionally dynamic printk debugging]
> instead.
[]
> +#define do_empty()		do { } while (0)

If this is really useful
(I think the warning is somewhat silly)

bikeshed:

I think do_nothing() is more descriptive