Description of problem:

when creating a direct lun from the disks sub tab, I am able to select a different DC than the DC selected for the vm. 
once I start the vm it will start in the correct DC/cluster but I still have an open session to it in the wrong DC. 

Version-Release number of selected component (if applicable):

si6

How reproducible:

100%

Steps to Reproduce:
1. create two DC's
2. add a vm on one of the DC's
3. create a direct lun and select the second DC in the selection roller. 
4. run the vm 
  
Actual results:

lun will be logged in on both Data centers/clusters

Expected results:

when creating a direct lun for a specific vm we should filter other DC's/clusters from the ones vm was created on. 

Additional info:screen shot+logs