msg: Move struct msg_queue into ipc/msg.c

All of the users are now in ipc/msg.c so make the definition local to
that file to make code maintenance easier.  AKA to prevent rebuilding
the entire kernel when struct msg_queue changes.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/ipc/msg.c b/ipc/msg.c
index cdfab08..af5a963 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -43,6 +43,23 @@
 #include <linux/uaccess.h>
 #include "util.h"
 
+/* one msq_queue structure for each present queue on the system */
+struct msg_queue {
+	struct kern_ipc_perm q_perm;
+	time64_t q_stime;		/* last msgsnd time */
+	time64_t q_rtime;		/* last msgrcv time */
+	time64_t q_ctime;		/* last change time */
+	unsigned long q_cbytes;		/* current number of bytes on queue */
+	unsigned long q_qnum;		/* number of messages in queue */
+	unsigned long q_qbytes;		/* max number of bytes on queue */
+	pid_t q_lspid;			/* pid of last msgsnd */
+	pid_t q_lrpid;			/* last receive pid */
+
+	struct list_head q_messages;
+	struct list_head q_receivers;
+	struct list_head q_senders;
+} __randomize_layout;
+
 /* one msg_receiver structure for each sleeping receiver */
 struct msg_receiver {
 	struct list_head	r_list;