icount sleep takes on or off as options. A few places mention sleep=no
which is not accepted. This patch corrects them.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <1456499811-16819-1-git-send-email-bobby.prani@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>