i40iw: Fix double free of allocated_buffer

Memory allocated for iwqp; iwqp->allocated_buffer is freed twice in
the create_qp error path. Correct this by having it freed only once in
i40iw_free_qp_resources().

Fixes: d374984179 ("i40iw: add files for iwarp interface")

Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/i40iw/i40iw_verbs.c

@@ -794,7 +794,6 @@ static struct ib_qp *i40iw_create_qp(struct ib_pd *ibpd,
 	return &iwqp->ibqp;
 error:
 	i40iw_free_qp_resources(iwdev, iwqp, qp_num);
-	kfree(mem);
 	return ERR_PTR(err_code);
 }