Remove an external port when an error occurs during FIP creation.
Remove an external port when an error occurs during FIP creation.

Fixes bug 1048140

To remove an external port, we need to use the same context used
when it is created.

Change-Id: Ia89b086b420741e7e0e92625b62e46fcfe9dbbba

gkotton/vmware-nsx,gkotton/vmware-nsx