build: Drop redundant _GNU_SOURCE definitions

It’s defined in `meson.build` now. See the previous commit.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

src/libsysprof-capture/sysprof-capture-writer.c

@@ -56,10 +56,6 @@
 
 #include "config.h"
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #include <assert.h>
 #include <endian.h>
 #include <errno.h>

src/libsysprof-capture/sysprof-collector.c

@@ -54,10 +54,6 @@
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #include <assert.h>
 #include <errno.h>
 #include <poll.h>

src/libsysprof-ui/sysprof-details-page.c

@@ -18,10 +18,6 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #define G_LOG_DOMAIN "sysprof-details-page"
 
 #include "config.h"

src/libsysprof-ui/sysprof-profiler-assistant.c

@@ -20,10 +20,6 @@
 
 #define G_LOG_DOMAIN "sysprof-profiler-assistant"
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #include "config.h"
 
 #include <sysprof.h>

src/libsysprof/preload/backtrace-helper.h

@@ -20,10 +20,6 @@
 
 #pragma once
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #ifdef HAVE_EXECINFO_H
 # include <execinfo.h>
 #endif

src/libsysprof/preload/sysprof-memory-collector.c

@@ -18,8 +18,6 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-#define _GNU_SOURCE
-
 #include "config.h"
 
 #include <dlfcn.h>

src/libsysprof/preload/sysprof-speedtrack-collector.c

@@ -18,8 +18,6 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-#define _GNU_SOURCE
-
 #include "config.h"
 
 #include <dlfcn.h>

src/libsysprof/sysprof-kallsyms.c

@@ -22,10 +22,6 @@
 
 #include "config.h"
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #include <errno.h>
 #include <string.h>
 #include <stdio.h>

src/sysprofd/sysprof-turbostat.c

@@ -18,8 +18,6 @@
  * SPDX-License-ntifier: GPL-3.0-or-later
  */
 
-#define _GNU_SOURCE
-
 #include "sysprof-turbostat.h"
 
 #include <errno.h>