Typo fixup in comment

## What changes were proposed in this pull request?

Fixup typo in comment.

## How was this patch tested?

Don't need.

Author: Ye Yin <eyniy@qq.com>

Closes #17396 from hustcat/fix.

resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosClusterManager.scala

@@ -22,7 +22,7 @@ import org.apache.spark.internal.config._
 import org.apache.spark.scheduler.{ExternalClusterManager, SchedulerBackend, TaskScheduler, TaskSchedulerImpl}
 
 /**
- * Cluster Manager for creation of Yarn scheduler and backend
+ * Cluster Manager for creation of Mesos scheduler and backend
  */
 private[spark] class MesosClusterManager extends ExternalClusterManager {
   private val MESOS_REGEX = """mesos://(.*)""".r