[PATCH] Fix error checking in IPC_SET

The LSM changes broke the error checking for queue lengths in IPC_SET. The LSM check would
set set err to 0, but the next check expected it to still be -EPERM. Result was that
no error was reported, but the new parameters weren't correctly set.

ipc/msg.c

@@ -557,6 +557,7 @@ asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds *buf)
 	switch (cmd) {
 	case IPC_SET:
 	{
+		err = -EPERM;
 		if (setbuf.qbytes > msg_ctlmnb && !capable(CAP_SYS_RESOURCE))
 			goto out_unlock_up;