Otherwise memory beyond irq_states[16] might be accessed.

Noticed by Juan Quintela.

Cc: stable@kernel.org
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Acked-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>