dm: Use uclass_first_device_err() where it is useful

Use this new function in places where it simplifies the code.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/ivybridge/sata.c b/arch/x86/cpu/ivybridge/sata.c
index a59d9ed..da6455b 100644
--- a/arch/x86/cpu/ivybridge/sata.c
+++ b/arch/x86/cpu/ivybridge/sata.c
@@ -229,11 +229,9 @@
 	struct udevice *pch;
 	int ret;
 
-	ret = uclass_first_device(UCLASS_PCH, &pch);
+	ret = uclass_first_device_err(UCLASS_PCH, &pch);
 	if (ret)
 		return ret;
-	if (!pch)
-		return -ENODEV;
 
 	if (!(gd->flags & GD_FLG_RELOC))
 		bd82x6x_sata_enable(dev);