No need to implement the same logic twice. Also check if the busy placements
are identical to the already scanned placements before checking them.

v2: improve check even more as suggested by Michel.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NNicolai Hähnle <nicolai.haehnle@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>