drm/amdgpu: Modify the count method of defer error

The number of newly added de counts and the number of
newly added error addresses remain consistent

Signed-off-by: Ce Sun <cesun102@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>