Fix path used in generatepot
Fix path used in generatepot

The generatepot script used to generate POT files for translation
still used an old pre-restructure path. This patch fixes to use doc

Change-Id: I18d3d85f4a51e3eabcd9475824a3cd53159a84b5

savinash47/openstack-doc-tools,savinash47/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools,openstack/openstack-doc-tools