VOL-5352 - AWS AMI recreation

Makefile
--------
  o Define venv-name=.venv to fix a repo:onf-make transition issue.
  o Chicken-n-egg problem for git submodule checkout.
  o Cannot clone git submodules when a submodule provides the definition
    for venv-name.  Short lived problem, makefile-origin/ can be removed
    once the makefile has fully transitioned over to repo:onf-make library
    logic.

Change-Id: I63f1118c42e86fe2e77e75bda4d103ec71d52ea2
diff --git a/Makefile b/Makefile
index 1aa69f5..079d82e 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@
 # -----------------------------------------------------------------------
 
 ifndef .DEFAULT_GOAL
-  .DEFAULT_GOAL := help # ?= help evaluated late
+  export .DEFAULT_GOAL := help # no->(?=), help target evaluated late
 endif
 MAKECMDGOALS    ?= help
 
@@ -34,6 +34,7 @@
 ifdef USE_LF_MK
   include lf/include.mk
 else
+  venv-name ?= .venv
   include lf/transition.mk
 endif # ifdef USE_LF_MK