Hardware only increments the put pointer on event types >= 4.  Do not
increment the get pointer for event type 3.
Reported-by: NKapil Karkra <kapil.karkra@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>