Enforce function declaration format in bash8

Check that function calls look like ^function foo {$ in bash8, and fix
all existing failures of that check.  Add a note to HACKING.rst

Change-Id: Ic19eecb39e0b20273d1bcd551a42fe400d54e938
diff --git a/lib/nova_plugins/hypervisor-openvz b/lib/nova_plugins/hypervisor-openvz
index fc5ed0c..a1636ad 100644
--- a/lib/nova_plugins/hypervisor-openvz
+++ b/lib/nova_plugins/hypervisor-openvz
@@ -27,13 +27,13 @@
 # ------------
 
 # clean_nova_hypervisor - Clean up an installation
-function cleanup_nova_hypervisor() {
+function cleanup_nova_hypervisor {
     # This function intentionally left blank
     :
 }
 
 # configure_nova_hypervisor - Set config files, create data dirs, etc
-function configure_nova_hypervisor() {
+function configure_nova_hypervisor {
     iniset $NOVA_CONF DEFAULT compute_driver "openvz.OpenVzDriver"
     iniset $NOVA_CONF DEFAULT connection_type "openvz"
     LIBVIRT_FIREWALL_DRIVER=${LIBVIRT_FIREWALL_DRIVER:-"nova.virt.libvirt.firewall.IptablesFirewallDriver"}
@@ -41,19 +41,19 @@
 }
 
 # install_nova_hypervisor() - Install external components
-function install_nova_hypervisor() {
+function install_nova_hypervisor {
     # This function intentionally left blank
     :
 }
 
 # start_nova_hypervisor - Start any required external services
-function start_nova_hypervisor() {
+function start_nova_hypervisor {
     # This function intentionally left blank
     :
 }
 
 # stop_nova_hypervisor - Stop any external services
-function stop_nova_hypervisor() {
+function stop_nova_hypervisor {
     # This function intentionally left blank
     :
 }