[CRIU] [PATCH] tools.mk: Define CC if not set to 'default'

[Cyrill Gorcunov]

On Thu, Apr 11, 2019 at 10:21:37AM +0100, Radostin Stoyanov wrote:
> 	FOO ?= bar
> 
> is equivalent to
> 
> 	ifeq ($(origin FOO), undefined)
> 	FOO = bar
> 	endif
> 
> However, when CC is not set its value is 'default' rather than
> 'undefined'.
>

Who set this value to "default"? This patch looks pretty wrong.