RDMA/qedr: Fix potential use after free

Move the release operation after error log to avoid possible use after
free.

Link: https://lore.kernel.org/r/1573021434-18768-1-git-send-email-bianpan2016@163.comSigned-off-by: Pan Bian <bianpan2016@163.com>
Acked-by: Michal Kalderon <michal.kalderon@marvell.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/qedr/qedr_iw_cm.c

@@ -481,10 +481,10 @@ qedr_addr6_resolve(struct qedr_dev *dev,
 
 	if ((!dst) || dst->error) {
 		if (dst) {
-			dst_release(dst);
 			DP_ERR(dev,
 			       "ip6_route_output returned dst->error = %d\n",
 			       dst->error);
+			dst_release(dst);
 		}
 		return -EINVAL;
 	}