Error for bad PVC specification

[mikemckiernan]

If the PVC isn't created, return predicted name rather than pvc.Name. IIUC, pvc is nil.

I had a bad PVC spec:

  storage:
    pvc:
      create: true
      storageClass: "nfs-client"
      volumeAccessMode: ReadWriteMany

The controller panicked:

2024-08-12T13:16:17Z    INFO    Observed a panic in reconciler: runtime error: invalid memory address or nil pointer dereference        {"controller": "nimcache", "controllerGroup": "apps.nvidia.com", "controllerKind": "NIMCache", "NIMCache": {"name":"meta-llama3-8b-instruct","namespace":"nim-service"}, "namespace": "nim-service", "name": "meta-llama3-8b-instruct", "reconcileID": "be258a8b-b3d7-405d-9d37-46c7f466635e"}
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x16766ea]
                                                                                                                        goroutine 259 [running]:
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Reconcile.func1()
        /workspace/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:111 +0x1e5
panic({0x17f9da0?, 0x29863a0?})
        /usr/local/go/src/runtime/panic.go:770 +0x132
github.com/NVIDIA/k8s-nim-operator/internal/controller.(*NIMCacheReconciler).reconcilePVC(0xc0004bdd60, {0x1cbc780, 0xc0007067b0}, 0xc000774008)
        /workspace/internal/controller/nimcache_controller.go:240 +0x32a