common object embedded into various struct ....ns

for now - just move corresponding ->proc_inum instances over there

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/ns_common.h

@@ -0,0 +1,8 @@
+#ifndef _LINUX_NS_COMMON_H
+#define _LINUX_NS_COMMON_H
+
+struct ns_common {
+	unsigned int inum;
+};
+
+#endif