[PATCH] docs: Remove broken link to Xen channel doc

[Michal Privoznik]

On 2/5/21 12:45 AM, Jim Fehlig wrote:
> Many of Xen's text documents have been converted to man pages over
> the years, the channel doc being one of them. Replace the broken
> channel.txt link with the name of the man page providing the same
> information.
> 
> Signed-off-by: Jim Fehlig <jfehlig at suse.com>
> ---
>   docs/formatdomain.rst | 9 ++++-----
>   1 file changed, 4 insertions(+), 5 deletions(-)

Reviewed-by: Michal Privoznik <mprivozn at redhat.com>

Michal