[PATCH] x86-64: Let oprofile reserve MSR on all CPUs

The MSR reservation is per CPU and oprofile would only allocate them
on the CPU it was initialized on. Change this to handle all CPUs.

This also fixes a warning about unprotected use of smp_processor_id()
in preemptible kernels.

Signed-off-by: Andi Kleen <ak@suse.de>