fix building crash driver on s390

[Josh Boyer]

On Tue, Nov 26, 2013 at 12:31:53PM +0100, Dan Horák wrote:
> Hi,
> 
> currently the crash driver is disabled in rawhide, but enabled as
> module in f20 and stabilization branch. The following snippet make it
> build on s390
> 
> diff -up a/arch/s390/mm/maccess.c.crash b/arch/s390/mm/maccess.c
> --- a/arch/s390/mm/maccess.c.crash	2013-11-26 10:51:55.188222879 -0500
> +++ b/arch/s390/mm/maccess.c	2013-11-26 10:52:43.718223592 -0500
> @@ -228,3 +228,6 @@ void unxlate_dev_mem_ptr(unsigned long a
>  	if ((void *) addr != buf)
>  		free_page((unsigned long) buf);
>  }
> +
> +EXPORT_SYMBOL(xlate_dev_mem_ptr);
> +EXPORT_SYMBOL(unxlate_dev_mem_ptr);
> 
> I think it should get appended to the crash driver patch.

Is this something anyone is in a position to test on s390x?  I'm fine
with adding it to the patch, but if nobody is going to use crash on
s390x I'm curious if we should leave it enabled.

josh