Revert "Handle Option.None correctly when removing an RDD"

This reverts commit 1710966b.

core/src/main/scala/org/apache/spark/storage/memory/MemoryStore.scala

@@ -396,13 +396,8 @@ private[spark] class MemoryStore(
 
   def remove(blockId: BlockId): Boolean = memoryManager.synchronized {
     val entry = entries.synchronized {
-      entries.get(blockId) match {
-        case Some(origEntry) =>
-          blockIdAndSizeSet -= new OurBlockIdAndSizeType(blockId, origEntry.size)
-        case None =>
-          // Do nothing
-          logInfo("origEntry was None after all")
-      }
+      val origEntry = entries.get(blockId)
+      blockIdAndSizeSet -= new OurBlockIdAndSizeType(blockId, origEntry.size)
       entries.remove(blockId)
     }
     if (entry != null) {