[PATCH] dup_fd() part 2

use alloc_fdtable() instead of expand_files(), get rid of pointless
grabbing newf->file_lock, kill magic in copy_fdtable() that used to
be there only to skip copying when called from dup_fd().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --cc fs/file.c
Simple merge