RDMA/efa: Remove redundant udata check from alloc ucontext response

The alloc ucontext flow is always called with a valid udata, there's no
need to test whether it's NULL.

While at it, the 'udata->outlen' check is removed as well as we copy the
minimum between the size of the response and outlen, so in case of zero
outlen, zero bytes will be copied.

Link: https://lore.kernel.org/r/20200818110835.54299-1-galpress@amazon.comReviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/efa/efa_verbs.c

@@ -1698,12 +1698,10 @@ int efa_alloc_ucontext(struct ib_ucontext *ibucontext, struct ib_udata *udata)
 	resp.max_tx_batch = dev->dev_attr.max_tx_batch;
 	resp.min_sq_wr = dev->dev_attr.min_sq_depth;
 
-	if (udata && udata->outlen) {
-		err = ib_copy_to_udata(udata, &resp,
-				       min(sizeof(resp), udata->outlen));
-		if (err)
-			goto err_dealloc_uar;
-	}
+	err = ib_copy_to_udata(udata, &resp,
+			       min(sizeof(resp), udata->outlen));
+	if (err)
+		goto err_dealloc_uar;
 
 	return 0;