[PATCH v2] selftests: execveat: Fix _GNU_SOURCE redefined build warn

[Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>]

Fix the following _GNU_SOURCE redefined build warn:

execveat.c:8: warning: "_GNU_SOURCE" redefined

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
No code changes. Sending to right people.

 tools/testing/selftests/exec/execveat.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/exec/execveat.c b/tools/testing/selftests/exec/execveat.c
index cbb6efbdb786..045a3794792a 100644
--- a/tools/testing/selftests/exec/execveat.c
+++ b/tools/testing/selftests/exec/execveat.c
@@ -5,7 +5,9 @@
  * Selftests for execveat(2).
  */
 
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE  /* to get O_PATH, AT_EMPTY_PATH */
+#endif
 #include <sys/sendfile.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
-- 
2.20.1