drm/amd: use drm_dbg_kms to log addfb2 failures

Avoid printing an error with dev_err, because user-space can trigger
these at will by issuing an ioctl.

Convert a DRM_DEBUG_KMS call to the more modern drm_dbg_kms macro.
Signed-off-by: Simon Ser <contact@emersion.fr>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Harry Wentland <hwentlan@amd.com>
Cc: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Cc: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_display.c

@@ -887,8 +887,8 @@ int amdgpu_display_framebuffer_init(struct drm_device *dev,
 	 */
 	for (i = 1; i < rfb->base.format->num_planes; ++i) {
 		if (mode_cmd->handles[i] != mode_cmd->handles[0]) {
-			dev_err(&dev->pdev->dev, "Plane 0 and %d have different BOs: %u vs. %u\n",
-				i, mode_cmd->handles[0], mode_cmd->handles[i]);
+			drm_dbg_kms(dev, "Plane 0 and %d have different BOs: %u vs. %u\n",
+				    i, mode_cmd->handles[0], mode_cmd->handles[i]);
 			ret = -EINVAL;
 			goto fail;
 		}
@@ -928,14 +928,14 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev,
 
 	obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[0]);
 	if (obj ==  NULL) {
-		dev_err(&dev->pdev->dev, "No GEM object associated to handle 0x%08X, "
-			"can't create framebuffer\n", mode_cmd->handles[0]);
+		drm_dbg_kms(dev, "No GEM object associated to handle 0x%08X, "
+			    "can't create framebuffer\n", mode_cmd->handles[0]);
 		return ERR_PTR(-ENOENT);
 	}
 
 	/* Handle is imported dma-buf, so cannot be migrated to VRAM for scanout */
 	if (obj->import_attach) {
-		DRM_DEBUG_KMS("Cannot create framebuffer from imported dma_buf\n");
+		drm_dbg_kms(dev, "Cannot create framebuffer from imported dma_buf\n");
 		return ERR_PTR(-EINVAL);
 	}