selftests: Makefile set KSFT_TAP_LEVEL to prevent nested TAP headers

Export KSFT_TAP_LEVEL and add TAP Header echo to the run_kselftest.sh
script from emit_tests target handling.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/Makefile

@@ -66,6 +66,12 @@ ifndef BUILD
   BUILD := $(shell pwd)
 endif
 
+# KSFT_TAP_LEVEL is used from KSFT framework to prevent nested TAP header
+# printing from tests. Applicable to run_tests case where run_tests adds
+# TAP header prior running tests and when a test program invokes another
+# with system() call. Export it here to cover override RUN_TESTS defines.
+export KSFT_TAP_LEVEL=`echo 1`
+
 export BUILD
 all:
 	@for TARGET in $(TARGETS); do		\
@@ -125,10 +131,12 @@ ifdef INSTALL_PATH
 	echo "else" >> $(ALL_SCRIPT)
 	echo "  OUTPUT=/dev/stdout" >> $(ALL_SCRIPT)
 	echo "fi" >> $(ALL_SCRIPT)
+	echo "export KSFT_TAP_LEVEL=`echo 1`" >> $(ALL_SCRIPT)
 
 	for TARGET in $(TARGETS); do \
 		BUILD_TARGET=$$BUILD/$$TARGET;	\
-		echo "echo ; echo Running tests in $$TARGET" >> $(ALL_SCRIPT); \
+		echo "echo ; echo TAP version 13" >> $(ALL_SCRIPT);	\
+		echo "echo Running tests in $$TARGET" >> $(ALL_SCRIPT); \
 		echo "echo ========================================" >> $(ALL_SCRIPT); \
 		echo "cd $$TARGET" >> $(ALL_SCRIPT); \
 		make -s --no-print-directory OUTPUT=$$BUILD_TARGET -C $$TARGET emit_tests >> $(ALL_SCRIPT); \