kern_linker.c: sort includes

This is preferred by style(9). Do this ahead of adding another include.

Reviewed by:	imp, kevans
MFC after:	3 days
Sponsored by:	NetApp, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D30185

sys/kern/kern_linker.c

@@ -34,27 +34,27 @@ __FBSDID("$FreeBSD$");
 #include "opt_hwpmc_hooks.h"
 
 #include <sys/param.h>
-#include <sys/kernel.h>
 #include <sys/systm.h>
-#include <sys/malloc.h>
-#include <sys/sysproto.h>
-#include <sys/sysent.h>
-#include <sys/priv.h>
-#include <sys/proc.h>
-#include <sys/lock.h>
-#include <sys/mutex.h>
-#include <sys/sx.h>
-#include <sys/module.h>
-#include <sys/mount.h>
-#include <sys/linker.h>
 #include <sys/eventhandler.h>
 #include <sys/fcntl.h>
 #include <sys/jail.h>
+#include <sys/kernel.h>
 #include <sys/libkern.h>
+#include <sys/linker.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/mount.h>
+#include <sys/mutex.h>
 #include <sys/namei.h>
-#include <sys/vnode.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/sx.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+#include <sys/vnode.h>
 
 #ifdef DDB
 #include <ddb/ddb.h>