sysctl: Don't compile sysctl_check when !CONFIG_SYSCTL

Weird I thought I had written the makefile so this would be handled.  Oh
well this should fix it.

Sorry about that.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-and-tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/Makefile

@@ -9,8 +9,9 @@ obj-y     = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
 	    rcupdate.o extable.o params.o posix-timers.o \
 	    kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
 	    hrtimer.o rwsem.o latency.o nsproxy.o srcu.o \
-	    utsname.o sysctl_check.o notifier.o
+	    utsname.o notifier.o
 
+obj-$(CONFIG_SYSCTL) += sysctl_check.o
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-y += time/
 obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o