In the function ttm_page_alloc_init, kzalloc call is made for variable
_manager, we need to check its return value, it may return NULL.
Signed-off-by: NXiongwei Song <sxwjean@gmail.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>