Properly wrap getOrElse in a tuple

(cherry picked from commit a7f7176)

Author: mccheah

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/scheduler/cluster/kubernetes/KubernetesClusterSchedulerBackend.scala

@@ -563,7 +563,7 @@ private[spark] class KubernetesClusterSchedulerBackend(
         mountSmallFilesBootstrap.map { bootstrap =>
           bootstrap.mountSmallFilesSecret(
             withMaybeShuffleConfigPod, withMaybeShuffleConfigExecutorContainer)
-        }.getOrElse(withMaybeShuffleConfigPod, withMaybeShuffleConfigExecutorContainer)
+        }.getOrElse((withMaybeShuffleConfigPod, withMaybeShuffleConfigExecutorContainer))
     val (executorPodWithInitContainer, initBootstrappedExecutorContainer) =
         executorInitContainerBootstrap.map { bootstrap =>
           val podWithDetachedInitContainer = bootstrap.bootstrapInitContainerAndVolumes(