Fix dump-vars output to handle quotes.

Bug: 132766811
Test: treehugger
Change-Id: I4c054343cd11a089d93b7386b8d8ba04a7b6b77e
diff --git a/core/dumpvar.mk b/core/dumpvar.mk
index 2f1023f..b2ee8fd 100644
--- a/core/dumpvar.mk
+++ b/core/dumpvar.mk
@@ -27,6 +27,6 @@
 .PHONY: dump-many-vars
 dump-many-vars :
 	@$(foreach v, $(DUMP_MANY_VARS),\
-	  echo "$(DUMP_VAR_PREFIX)$(v)='$($(v))'";)
+	  printf "%s='%s'\n" '$(DUMP_VAR_PREFIX)$(v)' '$($(v))';)
 
 endif # CALLED_FROM_SETUP