Use setenv(), safer and cleaner than putenv()

(cherry picked from commit 61f8e439)

bin/vlc.c

@@ -69,20 +69,19 @@ int main( int i_argc, const char *ppsz_argv[] )
      * LibVLC runs outside of VLC, we cannot rely on this code snippet. */
     signal (SIGPIPE, SIG_IGN);
 
-#ifdef HAVE_PUTENV
+#ifdef HAVE_SETENV
 # ifndef NDEBUG
     /* Activate malloc checking routines to detect heap corruptions. */
-    putenv( (char*)"MALLOC_CHECK_=2" );
+    setenv ("MALLOC_CHECK_", "2", 1);
 
     /* Disable the ugly Gnome crash dialog so that we properly segfault */
-    putenv( (char *)"GNOME_DISABLE_CRASH_DIALOG=1" );
+    setenv ("GNOME_DISABLE_CRASH_DIALOG", "1", 1);
 # endif
 
     /* Make Xlib hide visuals with an alphachannel. Ensure that Qt4 will not
      * use the alpha channel for the embedded video window. */
-    putenv( (char *)"XLIB_SKIP_ARGB_VISUALS=1" );
-#endif
-#ifdef HAVE_SETENV
+    setenv ("XLIB_SKIP_ARGB_VISUALS", "1", 1);
+
     /* Clear the X.Org startup notification ID. Otherwise the UI might try to
      * change the environment while the process is multi-threaded. That could
      * crash. Screw you X.Org. Next time write a thread-safe specification. */