syscall/ioctl: fix compiler error

"CLONE_NEWPID" and "CLONE_NEWUSER" are not defined on old distros
(kernel 2.6.18 and glibc 2.5), so include "lapi/namespaces_constants.h"
to fix it.

Signed-off-by: Jinhui huang <huangjh.jy@cn.fujitsu.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Petr Vorel <pvorel@suse.cz>

Author: Jinhui huang

testcases/kernel/syscalls/ioctl/ioctl_ns01.c

@@ -19,6 +19,7 @@
 #include <sched.h>
 #include "tst_test.h"
 #include "lapi/ioctl_ns.h"
+#include "lapi/namespaces_constants.h"
 
 #define STACK_SIZE (1024 * 1024)
 

testcases/kernel/syscalls/ioctl/ioctl_ns05.c

@@ -18,6 +18,7 @@
 #include <sched.h>
 #include "tst_test.h"
 #include "lapi/ioctl_ns.h"
+#include "lapi/namespaces_constants.h"
 
 #define STACK_SIZE (1024 * 1024)
 

testcases/kernel/syscalls/ioctl/ioctl_ns06.c

@@ -19,6 +19,7 @@
 #include <sched.h>
 #include "tst_test.h"
 #include "lapi/ioctl_ns.h"
+#include "lapi/namespaces_constants.h"
 
 #define STACK_SIZE (1024 * 1024)