xen/sched: Use %*pb[l] instead of cpumask_scn{,list}printf()

xen/sched: Use %*pb[l] instead of cpumask_scn{,list}printf()

This removes all use of keyhandler_scratch as a bounce-buffer for the rendered
string.  In some cases, collapse combine adjacent printk()'s which are writing
parts of the same line.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>