[PATCH] kselftest/alsa: Ensure _GNU_SOURCE is defined

[Mark Brown <broonie@xxxxxxxxxx>]

The pcmtest driver tests use the kselftest harness which requires that
_GNU_SOURCE is defined but nothing causes it to be defined.  Since the
KHDR_INCLUDES Makefile variable has had the required define added let's
use that, this should provide some futureproofing.

Fixes: daef47b89efd ("selftests: Compile kselftest headers with -D_GNU_SOURCE")
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 tools/testing/selftests/alsa/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/alsa/Makefile b/tools/testing/selftests/alsa/Makefile
index 5af9ba8a4645..c1ce39874e2b 100644
--- a/tools/testing/selftests/alsa/Makefile
+++ b/tools/testing/selftests/alsa/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 #
 
-CFLAGS += $(shell pkg-config --cflags alsa)
+CFLAGS += $(shell pkg-config --cflags alsa) $(KHDR_INCLUDES)
 LDLIBS += $(shell pkg-config --libs alsa)
 ifeq ($(LDLIBS),)
 LDLIBS += -lasound

---
base-commit: 3c999d1ae3c75991902a1a7dad0cb62c2a3008b4
change-id: 20240516-kselftest-fix-gnu-source-81ddd00870a8

Best regards,
-- 
Mark Brown <broonie@xxxxxxxxxx>