makeparallel: prepend flags to ninja command line

Ninja stops parsing top level options after -t is used to select a
tool.  Put any inserted command line options at the beginning of the
command.

Change-Id: I2ba903143366aaded63e21d749476248617c8962
diff --git a/tools/makeparallel/Makefile.test b/tools/makeparallel/Makefile.test
index 91aacf7..cf53684 100644
--- a/tools/makeparallel/Makefile.test
+++ b/tools/makeparallel/Makefile.test
@@ -3,7 +3,7 @@
 .PHONY: test
 test:
 	@+echo MAKEFLAGS=$${MAKEFLAGS};              \
-	result=$$($(MAKEPARALLEL) echo);             \
+	result=$$($(MAKEPARALLEL) echo $(ARGS));     \
 	echo result: $${result};                     \
 	if [ "$${result}" = "$(EXPECTED)" ]; then    \
 	  echo SUCCESS && echo;                      \