btrfs: factor out helper for counting data stripes

Factor the sequence of ifs to a helper, the 'data stripes' here means
the number of stripes without redundancy and parity.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2019-05-17 11:43:34 +02:00
commit 946c9256c6