Revert "Fixup ->open_files if not given"

This reverts commit bcd27f7ae1ccebd2ac1778752bf8f13fa99600e9.

The commit causes us to default to 1 file for cases where
openfiles= isn't set, where before we would default to
nr_files.

Signed-off-by: Jens Axboe <axboe@fb.com>

Conflicts:
	filesetup.c
Increment open file count manually

For engines/logs that manually add files, be sure to increment
the open file count.

Signed-off-by: Jens Axboe <axboe@fb.com>
server: fix fd leak in error case

Signed-off-by: Jens Axboe <axboe@fb.com>
diskutil: fix potential out-of-bounds array write

Signed-off-by: Jens Axboe <axboe@fb.com>
iolog: skip max_bs[rw] increment for rw == DDIR_INVAL

Signed-off-by: Jens Axboe <axboe@fb.com>