Btrfs-progs: only build space info's for the main flags

Btrfs-progs: only build space info's for the main flags

Hitting enospc problems with a really corrupt fs uncovered the fact that we
match any flag in a block group when creating space info's.  This is a problem
if we have a raid level set, we'll end up with only one space info that covers
metadata and data because they share a raid level.  We don't want this, we want
to separate out the data and metadata space infos, so mask off the raid level
and only use the main flags.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>