Pull UML updates from Richard Weinberger:
- removal of old and dead code
- a bug fix for our tty driver
- other minor cleanups across the code base
* 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Make line/tty semantics use true write IRQ
um: trap: fix spelling mistake, EACCESS -> EACCES
um: Don't hardcode path as it is architecture dependent
um: NULL check before kfree is not needed
um: remove unused AIO code
um: Give start_idle_thread() a return code
um: Remove update_debugregs()
um: Drop own definition of PTRACE_SYSEMU/_SINGLESTEP