ovs-vsctl: Improve error message for "ovs-vsctl del-port <bridge>".
Previously, commands like this:
ovs-vsctl add-br br0
ovs-vsctl del-port br0
yielded an error message like:
no port named br0
which is confusing. This commit improves the error message to:
cannot delete port br0 because it is the local port for bridge br0
(deleting this port requires deleting the entire bridge)
Bug #17994. Reported-by: Reid Price <reid@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com>