[PATCH] Documentation: kunit: Fix kunit_device_register() example

[Robin Murphy <robin.murphy@arm.com>]

kunit_device_register() only returns error pointers, not NULL.
Furthermore for regular users who aren't testing the KUnit API
itself, errors most likely represent major system failure (e.g. OOM
or sysfs collision) beyond the scope of their own test conditions.
Replace the assert with straightforward error handling for clarity.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
This seemed the logical conclusion by inspection, but please do correct
me if I've misunderstood the intent...
---
 Documentation/dev-tools/kunit/usage.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index 038f480074fd..3452c739dd44 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -873,7 +873,8 @@ For example:
 
 		// Create a fake device.
 		fake_device = kunit_device_register(test, "my_device");
-		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_device)
+		if (IS_ERR(fake_device))
+			return;
 
 		// Pass it to functions which need a device.
 		dev_managed_string = devm_kstrdup(fake_device, "Hello, World!");
-- 
2.34.1