i40iw: Fix memory leak in error path of create QP

commit 5a7189d5 upstream.

If i40iw_allocate_dma_mem fails when creating a QP, the
memory allocated for the QP structure using kzalloc is not
freed because iwqp->allocated_buffer is used to free the
memory and it is not setup until later. Fix this by setting
iwqp->allocated_buffer before allocating the dma memory.

Fixes: d3749841 ("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>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/infiniband/hw/i40iw/i40iw_verbs.c

@@ -631,6 +631,7 @@ static struct ib_qp *i40iw_create_qp(struct ib_pd *ibpd,
 		return ERR_PTR(-ENOMEM);
 
 	iwqp = (struct i40iw_qp *)mem;
+	iwqp->allocated_buffer = mem;
 	qp = &iwqp->sc_qp;
 	qp->back_qp = (void *)iwqp;
 	qp->push_idx = I40IW_INVALID_PUSH_PAGE_INDEX;
@@ -659,7 +660,6 @@ static struct ib_qp *i40iw_create_qp(struct ib_pd *ibpd,
 		goto error;
 	}
 
-	iwqp->allocated_buffer = mem;
 	iwqp->iwdev = iwdev;
 	iwqp->iwpd = iwpd;
 	iwqp->ibqp.qp_num = qp_num;