mount/mount06.c: fix a compile error

The definitions of MS_PRIVATE and MS_MOVE were only added to glibc headers
in version 2.12.

If there are no definitions of these two flags, make it.

Signed-off-by: DAN LI <li.dan@cn.fujitsu.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
diff --git a/testcases/kernel/syscalls/mount/mount06.c b/testcases/kernel/syscalls/mount/mount06.c
index acfb22d..fff6483 100644
--- a/testcases/kernel/syscalls/mount/mount06.c
+++ b/testcases/kernel/syscalls/mount/mount06.c
@@ -31,6 +31,14 @@
 #include "usctest.h"
 #include "safe_macros.h"
 
+#ifndef MS_MOVE
+#define MS_MOVE	8192
+#endif
+
+#ifndef MS_PRIVATE
+#define MS_PRIVATE	(1 << 18)
+#endif
+
 #define MNTPOINT_SRC	"mnt_src"
 #define MNTPOINT_DES	"mnt_des"
 #define LINELENGTH	256