Create /etc/openvswitch dir when package is installed.

Create /etc/openvswitch dir when package is installed.

Earlier, the /etc/openvswitch directory would get installed as part of
the init script's start sequence. However, as newer packages are added,
including some that create files in this directory during their init
script sequences, a race condition may occur.

This change ensures that the directory /etc/openvswitch is created even
before the init scripts execute. Thus, the race condition is avoided.