desktop-shell: use the standard 'environ' variable

The variable '__environ' seems to be libc implementation specific, and
not avaible on Android.

Use the POSIX standard variable 'environ', which also luckily happens to
be available on Android, which is not POSIX.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

clients/desktop-shell.c

@@ -44,6 +44,8 @@
 
 #include "desktop-shell-client-protocol.h"
 
+extern char **environ; /* defined by libc */
+
 struct desktop {
 	struct display *display;
 	struct desktop_shell *shell;
@@ -484,9 +486,9 @@ panel_add_launcher(struct panel *panel, const char *icon, const char *path)
 
 	wl_array_init(&launcher->envp);
 	wl_array_init(&launcher->argv);
-	for (i = 0; __environ[i]; i++) {
+	for (i = 0; environ[i]; i++) {
 		ps = wl_array_add(&launcher->envp, sizeof *ps);
-		*ps = __environ[i];
+		*ps = environ[i];
 	}
 	j = 0;