datapath-windows: Fixes in HvCreatePort() to re-add a port

datapath-windows: Fixes in HvCreatePort() to re-add a port

In this patch, we update HvCreatePort() to be able to re-add a Hyper-V
port. Specifically, we handle the case where the port had also been
added by OVS userspace, so that when the port was previously deleted
from Hyper-V, we did not deallocate the port.

The key to a vport is its name. We lookup the list of vports both in the
'portIdHashArray' as well as 'portNoHashArray' to make sure that we
don't have a port with the same name.

Validation:
- deleted an re-added a port with and without the corresponding OVS port
existing
- deleted, changed the name of a port, and re-added it back with and
without the corresponding OVS port existing.
- uninstall was succcessful. No asserts hit.

Signed-off-by: Nithin Raju <nithin@vmware.com>
Acked-by: Ankur Sharma <ankursharma@vmware.com>
Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>