KVM: PPC: Book3s: PR: No irq_disable in vcpu_run

Somewhere during merges we ended up from

  local_irq_enable()
  foo();
  local_irq_disable()

to always keeping irqs enabled during that part. However, we now
have the following code:

  foo();
  local_irq_disable()

which disables interrupts without the surrounding code enabling them
again! So let's remove that disable and be happy.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>