ovs-vswitchd.conf.db is distributed so it's in the source directory not
the build directory.
This fixes a Debian package build failure introduced by commit
9840bdbd
"debian: Install ovs-vswitchd.conf.db(5) manpage." I did test that commit
but the build failure didn't show up in my environment (probably I had a
stray file left over from development).
_debian/utilities/ovs-vlan-test.8
_debian/utilities/ovs-vsctl.8
_debian/vswitchd/ovs-vswitchd.8
-_debian/vswitchd/ovs-vswitchd.conf.db.5
+vswitchd/ovs-vswitchd.conf.db.5