IB/hfi1: Fix pio wait counter double increment

The code unconditionlly increments the pio wait counter
making the counter inacurate and unusable.

Fixes: 14553ca1 ("staging/rdma/hfi1: Adaptive PIO for short messages")
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/staging/rdma/hfi1/verbs.c

@@ -946,7 +946,6 @@ static int pio_wait(struct rvt_qp *qp,
 
 			dev->n_piowait += !!(flag & RVT_S_WAIT_PIO);
 			dev->n_piodrain += !!(flag & RVT_S_WAIT_PIO_DRAIN);
-			dev->n_piowait++;
 			qp->s_flags |= flag;
 			was_empty = list_empty(&sc->piowait);
 			list_add_tail(&priv->s_iowait.list, &sc->piowait);