btrfs: use raid_attr to get allowed profiles for balance conversion

Iterate over the table and gather all allowed profiles for a given
number of devices, instead of open coding.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2019-05-17 11:43:27 +02:00
commit 081db89b13