[Piglit] [PATCH] ext_transform_feedback-api-errors: Silence _GNU_SOURCE redefined warning.

[Vinson Lee]

Fixes GCC warning.

api-errors.c:51:0: warning: "_GNU_SOURCE" redefined [enabled by default]
 #define _GNU_SOURCE
 ^
<command-line>:0:0: note: this is the location of the previous definition

Signed-off-by: Vinson Lee <vlee at freedesktop.org>
---
 tests/spec/ext_transform_feedback/api-errors.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/spec/ext_transform_feedback/api-errors.c b/tests/spec/ext_transform_feedback/api-errors.c
index 752187d..c8d65c4 100644
--- a/tests/spec/ext_transform_feedback/api-errors.c
+++ b/tests/spec/ext_transform_feedback/api-errors.c
@@ -48,7 +48,9 @@
  * implementation is not overly aggressive in flagging errors.
  */
 
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif
 #include "piglit-util-gl-common.h"
 
 PIGLIT_GL_TEST_CONFIG_BEGIN
-- 
1.8.3.2