Reduce duplicate imports of functions & stackrc

In devstack openrc -> stackrc -> functions

I think it's fair to say nobody is really thinking about idempotency
when they write these rc files; it's assumed they're sourced once
per-run.  I3ca4e576aa3fb8992c08ca44900a8c53dd4b4163 is an example of
this.

Reduce some of the duplicate imports here by just importing the
top-level (either openrc if that's wanted, or stackrc)

Change-Id: I6fbae12f950a03afab39f341132746d3db9f788c

clean.sh

@@ -29,7 +29,6 @@ set -o xtrace
 if [[ -d $BASE_DEVSTACK_DIR ]]; then
     bash -c "
         cd $BASE_DEVSTACK_DIR; \
-        source functions; \
         source stackrc; \
         source lib/tls; \
         source lib/cinder; \
@@ -47,7 +46,6 @@ fi
 if [[ -d $TARGET_DEVSTACK_DIR ]]; then
     bash -x -c "
         cd $TARGET_DEVSTACK_DIR; \
-        source functions; \
         source stackrc; \
         source lib/tls; \
         source lib/cinder; \

inc/upgrade

@@ -53,7 +53,6 @@ function upgrade_service {
         enabled="True"
     else
         enabled=$(
-            source $TARGET_DEVSTACK_DIR/functions;
             source $TARGET_DEVSTACK_DIR/stackrc;
             is_service_enabled $local_service || echo "False")
     fi

prep-target

@@ -29,8 +29,7 @@ if [[ -d $BASE_RELEASE_DIR/images ]]; then
     rsync -a $BASE_RELEASE_DIR/images $TARGET_DEVSTACK_DIR/files
 fi
 
-# Get target config
-source $TARGET_DEVSTACK_DIR/functions
+# Get target config (stackrc grabs devstack "functions" too)
 source $TARGET_DEVSTACK_DIR/stackrc
 
 # Build a wheel cache

upgrade-tempest

@@ -40,8 +40,7 @@ GetDistro
 TOP_DIR=$TARGET_DEVSTACK_DIR
 
 cd $TARGET_DEVSTACK_DIR
-source $TARGET_DEVSTACK_DIR/functions
-source $TARGET_DEVSTACK_DIR/stackrc
+ # note; openrc sources functions & stackrc
 source $TARGET_DEVSTACK_DIR/openrc
 FILES=$TARGET_DEVSTACK_DIR/files