Description of problem:
When deleting the snapshot disks and reboot the host during this operation the EndAction for RemoveSnapshotDisks end with a Null Pointer Exception

Version-Release number of selected component (if applicable):
ovirt-engine-3.5.0-0.0.master.20140821064931.gitb794d66.el6.noarch
vdsm-4.16.1-6.gita4a4614.el6.x86_64

How reproducible:
All the time

Steps to Reproduce:
1.add vm + 3 disks,create a snapshot
2.add another 2 disks and create another snapshot
3.select all volumes from snapshot overview and remove them
4.during removal reboot host

Actual results:
The endAction for action type RemoveDiskSnapshots threw an exception

Expected results:
The End Action should have completed and rolled back the failed delete operation

Additional info:
FROM ENGINE LOG>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>...
https://tcms.engineering.redhat.com/run/163708/
n of Disk 'vm10_Disk5' from snapshot(s) 'vm10_snap2' of VM 'vm10' (User: admin).
2014-08-27 10:34:49,578 ERROR [org.ovirt.engine.core.bll.tasks.CommandAsyncTask] (org.ovirt.thread.pool-8-thread-47) [within thread]: endAction for action type RemoveDiskSnapshots threw an exception.: java.lang.NullPointerException
        at org.ovirt.engine.core.bll.RemoveDiskSnapshotTaskHandler.endWithFailure(RemoveDiskSnapshotTaskHandler.java:103) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.internalEndWithFailure(CommandBase.java:653) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.endActionInTransactionScope(CommandBase.java:566) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.runInTransaction(CommandBase.java:1923) [bll.jar:]
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInNewTransaction(TransactionSupport.java:210) [utils.jar:]
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInRequired(TransactionSupport.java:149) [utils.jar:]
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInScope(TransactionSupport.java:118) [utils.jar:]
        at org.ovirt.engine.core.bll.CommandBase.endAction(CommandBase.java:494) [bll.jar:]
        at org.ovirt.engine.core.bll.tasks.DecoratedCommand.endAction(DecoratedCommand.java:17) [bll.jar:]
        at org.ovirt.engine.core.bll.tasks.CoCoAsyncTaskHelper.endAction(CoCoAsyncTaskHelper.java:323) [bll.jar:]
        at org.ovirt.engine.core.bll.tasks.CommandCoordinatorImpl.endAction(CommandCoordinatorImpl.java:350) [bll.jar:]
        at org.ovirt.engine.core.bll.tasks.CommandAsyncTask.endCommandAction(CommandAsyncTask.java:149) [bll.jar:]
        at org.ovirt.engine.core.bll.tasks.CommandAsyncTask.access$000(CommandAsyncTask.java:28) [bll.jar:]
        at org.ovirt.engine.core.bll.tasks.CommandAsyncTask$1.run(CommandAsyncTask.java:109) [bll.jar:]
        at org.ovirt.engine.core.utils.threadpool.ThreadPoolUtil$InternalWrapperRunnable.run(ThreadPoolUtil.java:90) [utils.jar:]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [rt.jar:1.7.0_55]
        at java.util.concurrent.FutureTask.run(FutureTask.java:262) [rt.jar:1.7.0_55]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_55]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_55]
        at java.lang.Thread.run(Thread.java:744) [rt.jar:1.7.0_55]