arch/um/drivers/chan_kern.c::chan_out_fd() is not used by anyone.  Remove it.
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NWANG Cong <wangcong@zeuux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>