dra scheduler: ensure that we never have nil Claim/Class parameters

Without this, the scheduler was crashing in newClaimController() in
pkg/scheduler/framework/plugins/dynamicresources/structuredparameters.go

The code in newClaimController() assumes that the parameters are not
nil.  We could add a check in here to react differently if they are nil,
but its probably better to just ensure they are never nil in the first
place.

Signed-off-by: Kevin Klues <kklues@nvidia.com>

pkg/scheduler/framework/plugins/dynamicresources/dynamicresources.go

@@ -969,7 +969,7 @@ func (pl *dynamicResources) lookupParameters(logger klog.Logger, class *resource
 
 func (pl *dynamicResources) lookupClassParameters(logger klog.Logger, class *resourcev1alpha2.ResourceClass) (*resourcev1alpha2.ResourceClassParameters, *framework.Status) {
 	if class.ParametersRef == nil {
-		return nil, nil
+		return &resourcev1alpha2.ResourceClassParameters{}, nil
 	}
 
 	if class.ParametersRef.APIGroup == resourcev1alpha2.SchemeGroupVersion.Group &&
@@ -1006,7 +1006,7 @@ func (pl *dynamicResources) lookupClassParameters(logger klog.Logger, class *res
 
 func (pl *dynamicResources) lookupClaimParameters(logger klog.Logger, claim *resourcev1alpha2.ResourceClaim) (*resourcev1alpha2.ResourceClaimParameters, *framework.Status) {
 	if claim.Spec.ParametersRef == nil {
-		return nil, nil
+		return &resourcev1alpha2.ResourceClaimParameters{}, nil
 	}
 	if claim.Spec.ParametersRef.APIGroup == resourcev1alpha2.SchemeGroupVersion.Group &&
 		claim.Spec.ParametersRef.Kind == "ResourceClaimParameters" {