[PATCH v2] drm/i915/selftests: fix NULL vs IS_ERR() check in mock_context_barrier()

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

The mock_context() function returns NULL on error, it doesn't return
error pointers.

Fixes: 85fddf0b0027 ("drm/i915: Introduce a context barrier callback")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
V2: I accidentally sent a bunch of unrelated stuff...

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
index 4399ef9ebf15..a172dbd9cb9e 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
@@ -1620,8 +1620,8 @@ static int mock_context_barrier(void *arg)
 	mutex_lock(&i915->drm.struct_mutex);
 
 	ctx = mock_context(i915, "mock");
-	if (IS_ERR(ctx)) {
-		err = PTR_ERR(ctx);
+	if (!ctx) {
+		err = -ENOMEM;
 		goto unlock;
 	}