drm/amdgpu: fix metadata_size for ubo ioctl queries

Although the kfd_ioctl_get_dmabuf_info() still fail it will indicate
the caller right metadat_size useful for the same kfd ioctl next time.
Signed-off-by: NShiwu Zhang <shiwu.zhang@amd.com>
Reviewed-by: NNirmoy Das <nirmoy.das@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -1197,6 +1197,9 @@ int amdgpu_bo_get_metadata(struct amdgpu_bo *bo, void *buffer,
 
 	BUG_ON(bo->tbo.type == ttm_bo_type_kernel);
 	ubo = to_amdgpu_bo_user(bo);
+	if (metadata_size)
+		*metadata_size = ubo->metadata_size;
+
 	if (buffer) {
 		if (buffer_size < ubo->metadata_size)
 			return -EINVAL;
@@ -1205,8 +1208,6 @@ int amdgpu_bo_get_metadata(struct amdgpu_bo *bo, void *buffer,
 			memcpy(buffer, ubo->metadata, ubo->metadata_size);
 	}
 
-	if (metadata_size)
-		*metadata_size = ubo->metadata_size;
 	if (flags)
 		*flags = ubo->metadata_flags;