From: Julien Grall <jgrall@amazon.com>

The steps to generate the documentation for the new branch requires
to ssh as root and then su to run with the user xendocs.

The release technician may not (and should not) have access to root.
So update the step to directly ssh as xendocs.

Signed-off-by: Julien Grall <jgrall@amazon.com>