selftests: futex: set DEFAULT_INSTALL_HDR_PATH

If only futex selftest is compiled, uapi header files are copied to the
selftests/futex/functional directory. This copy isn't needed. Set the
DEFAULT_INSTALL_HDR_PATH variable to 1 to use the default header install
path only. This removes extra copy of header file.
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/futex/functional/Makefile

@@ -24,6 +24,7 @@ TEST_PROGS := run.sh
 
 top_srcdir = ../../../../..
 KSFT_KHDR_INSTALL := 1
+DEFAULT_INSTALL_HDR_PATH := 1
 include ../../lib.mk
 
 $(TEST_GEN_FILES): $(HEADERS)