Remove unnecessary/redundant includes.

Approved by:	bz (mentor)

sys/kern/kern_cpuset.c

@@ -49,7 +49,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/syscallsubr.h>
 #include <sys/cpuset.h>
 #include <sys/sx.h>
-#include <sys/refcount.h>
 #include <sys/queue.h>
 #include <sys/limits.h>
 #include <sys/bus.h>

sys/kern/uipc_usrreq.c

@@ -67,7 +67,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/eventhandler.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>
-#include <sys/jail.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
 #include <sys/mbuf.h>