xen: delete new instances of __cpuinit usage

xen: delete new instances of __cpuinit usage

Commit 1fe565517b57676884349dccfd6ce853ec338636 ("xen/events: use
the FIFO-based ABI if available") added new instances of __cpuinit
macro usage.

We removed this a couple versions ago; we now want to remove
the compat no-op stubs.  Introducing new users is not what
we want to see at this point in time, as it will break once
the stubs are gone.

Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>