IB/iser: Fix redundant pointer check in dealloc flow

This bug was discovered by Smatch static checker run by Dan Carpenter.
If in free_rx_descriptors(), rx_descs are not NULL then the iser
device is definately not NULL, so no need to check it before
dereferencing it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/ulp/iser/iser_initiator.c

@@ -310,7 +310,7 @@ void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 	if (!ib_conn->rx_descs)
 		goto free_login_buf;
 
-	if (device && device->iser_free_rdma_reg_res)
+	if (device->iser_free_rdma_reg_res)
 		device->iser_free_rdma_reg_res(ib_conn);
 
 	rx_desc = ib_conn->rx_descs;