[PATCH 22/34] selftests: ptp: Fix incorrect kernel headers search path

[Mathieu Desnoyers]

Use $(KHDR_INCLUDES) as lookup path for kernel headers. This prevents
building against kernel headers from the build environment in scenarios
where kernel headers are installed into a specific output directory
(O=...).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>    [5.18+]
---
 tools/testing/selftests/ptp/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ptp/Makefile b/tools/testing/selftests/ptp/Makefile
index ef06de0898b7..eeab44cc6863 100644
--- a/tools/testing/selftests/ptp/Makefile
+++ b/tools/testing/selftests/ptp/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-CFLAGS += -I../../../../usr/include/
+CFLAGS += $(KHDR_INCLUDES)
 TEST_PROGS := testptp
 LDLIBS += -lrt
 all: $(TEST_PROGS)
-- 
2.25.1