tests: playback: include stdlib.h unconditionally

Like we do elsewhere. And drop the check for the header.
Also remove some superfluous unistd.h includes.

meson.build

@@ -115,7 +115,6 @@ check_headers = [
   ['HAVE_PROCESS_H', 'process.h'],
   ['HAVE_SMMINTRIN_H', 'smmintrin.h'],
   ['HAVE_STDINT_H', 'stdint.h'],
-  ['HAVE_STDLIB_H', 'stdlib.h'],
   ['HAVE_STRINGS_H', 'strings.h'],
   ['HAVE_STRING_H', 'string.h'],
   ['HAVE_SYS_SOCKET_H', 'sys/socket.h'],

tests/icles/playback/test4.c

@@ -19,12 +19,8 @@
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
-#ifdef HAVE_STDLIB_H
+
 #include <stdlib.h>             /* exit() */
-#endif
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
 
 #include <gst/gst.h>
 

tests/icles/playback/test5.c

@@ -19,12 +19,9 @@
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-#ifdef HAVE_STDLIB_H
+
 #include <stdlib.h>             /* exit */
-#endif
+
 #include <gst/gst.h>
 
 static GMainLoop *loop;

tests/icles/playback/test6.c

@@ -19,12 +19,9 @@
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-#ifdef HAVE_STDLIB_H
+
 #include <stdlib.h>             /* exit */
-#endif
+
 #include <gst/gst.h>
 
 static void

tests/icles/playback/test7.c

@@ -19,9 +19,7 @@
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
-#ifdef HAVE_STDLIB_H
 #include <stdlib.h>             /* exit() */
-#endif
 #include <gst/gst.h>
 
 #define UPDATE_INTERVAL 500