Issue: vrf delete timeout.

vrf get from deleted VN fails some times and in turn
results in failure to remove exported route path from OVS

Fix: while deleting the exported route path use direct
reference to vrf instead of getting it from VN.

Change-Id: I24b1da4cfa6cf4c60f6985b0ec44a28dbb5fa1d6
Merge "Issue: vrf delete timeout."