Add kernel/notifier.c

There is separate notifier header, but no separate notifier .c file.

Extract notifier code out of kernel/sys.c which will remain for
misc syscalls I hope. Merge kernel/die_notifier.c into kernel/notifier.c.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/notifier.h

@@ -240,5 +240,7 @@ static inline int notifier_to_errno(int ret)
 #define KBD_KEYSYM		0x0004 /* Keyboard keysym */
 #define KBD_POST_KEYSYM		0x0005 /* Called after keyboard keysym interpretation */
 
+extern struct blocking_notifier_head reboot_notifier_list;
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_NOTIFIER_H */

kernel/Makefile

@@ -8,8 +8,8 @@ obj-y     = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
 	    signal.o sys.o kmod.o workqueue.o pid.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 die_notifier.o \
-	    utsname.o sysctl_check.o
+	    hrtimer.o rwsem.o latency.o nsproxy.o srcu.o \
+	    utsname.o sysctl_check.o notifier.o
 
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-y += time/