cifs: convert booleans in cifsInodeInfo to a flags field

In later patches, we'll need to have a bitlock, so go ahead and convert
these bools to use atomic bitops instead.

Also, clean up the initialization of the flags field. There's no need
to unset each bit individually just after it was zeroed on allocation.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Steve French <smfrench@gmail.com>