ibverbs/rxe: Remove variable self-initialization

In some cases (not in this particular one) variable self-initialization
can lead to undefined behavior. In this case, it is just obscure code.
Signed-off-by: Maksym Planeta <mplaneta@os.inf.tu-dresden.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/rxe/rxe_comp.c

@@ -558,7 +558,7 @@ int rxe_completer(void *arg)
 {
 	struct rxe_qp *qp = (struct rxe_qp *)arg;
 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
-	struct rxe_send_wqe *wqe = wqe;
+	struct rxe_send_wqe *wqe = NULL;
 	struct sk_buff *skb = NULL;
 	struct rxe_pkt_info *pkt = NULL;
 	enum comp_state state;