btsnoop: _GNU_SOURCE is needed for O_CLOEXEC on some systems

diff --git a/tools/btsnoop.c b/tools/btsnoop.c
index dcb4a26..0a01adf 100644 (file)
--- a/tools/btsnoop.c
+++ b/tools/btsnoop.c
@@ -26,6 +26,7 @@
 #include <config.h>
 #endif
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <errno.h>
 #include <fcntl.h>