lib: Create $(sysconfdir)/openvswitch upon install

In cases where dbdir and etcdir are not the same, there is a need
for creating etcdir (i.e. $(sysconfdir)/openvswitch) explicitly.

Note that there is no attempt being made here to make the etcdir
configurable as in "--with-dbdir".

Reported-at: http://openvswitch.org/pipermail/dev/2016-September/TBD.html
Fixes: f973f2a ("Make the location of the database separately configurable.")
Signed-off-by: Flavio Fernandes <flavio@flaviof.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

lib/automake.mk

@@ -528,3 +528,4 @@ lib-install-data-local:
 	$(MKDIR_P) $(DESTDIR)$(PKIDIR)
 	$(MKDIR_P) $(DESTDIR)$(LOGDIR)
 	$(MKDIR_P) $(DESTDIR)$(DBDIR)
+	$(MKDIR_P) $(DESTDIR)$(sysconfdir)/openvswitch