Merge branch 'rework/kthreads' into for-linus

diff --cc drivers/tty/sysrq.c
Simple merge

diff --cc include/linux/printk.h
Simple merge

diff --cc kernel/hung_task.c
Simple merge

diff --cc kernel/panic.c
Simple merge

diff --cc kernel/reboot.c
Simple merge

diff --cc kernel/watchdog.c
Simple merge