Fix tests on Android

src/tests/concurrent.c

@@ -125,6 +125,8 @@ static void *concurrent(void *arguments)
 {
     do_function(arguments);
     pthread_exit(NULL);
+
+    return NULL;
 }
 
 int main(int argc, char *argv[]) {

src/tests/console.c

@@ -23,6 +23,7 @@
 
 #include <errno.h>
 #include <unistd.h>
+#include <stdio.h>
 
 #define TTYCNT      4
 #define TTYCNT_STR "4"

src/tests/reboot.c

@@ -25,7 +25,8 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 
-#define _GNU_SOURCE
+#include <lxc/namespace.h>
+
 #include <sched.h>
 #include <linux/sched.h>
 #include <linux/reboot.h>

src/tests/snapshot.c

@@ -20,6 +20,7 @@
 
 #include <errno.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include "../lxc/lxc.h"
 
 #define MYNAME "snapxxx1"