ovsdb: Tweak interface whitespace formatting
ovsdb: Tweak interface whitespace formatting

It's easier to read the method definitions, especially as we add more
methods.

NetSys/quilt,quilt/quilt,ejj/quilt-dev,NetSys/quilt,LuiseV/quilt,kklin/quilt,kklin/quilt,quilt/quilt,LuiseV/quilt,kklin/quilt,quilt/quilt,LuiseV/quilt,kelda/kelda,kklin/kelda,kayousterhout/quilt,NetSys/quilt,kayousterhout/quilt,kklin/kelda,kklin/kelda,kelda/kelda,kklin/kelda,ejj/quilt-dev,kklin/quilt,ejj/quilt-dev,NetSys/quilt,ejj/quilt-dev,LuiseV/quilt,LuiseV/quilt,NetSys/quilt,kelda/kelda,kelda/kelda,kayousterhout/quilt,quilt/quilt,kayousterhout/quilt