xfs_repair: write both features2 fields when xfs_admin changes lazy_count

xfs_repair: write both features2 fields when xfs_admin changes lazy_count

xfs_admin -c invokes repair directly to change lazy_count,
but it doesn't write both features2 fields, so this:

# mkfs.xfs -dfile,name=fsfile,size=10g -llazy-count=0
# xfs_admin -c 1 fsfile
# xfs_repair fsfile

yields errors.

Reported-by: Marcin Mirosław <marcin@mejor.pl>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Dave Chinner <david@fromorbit.com>