btrfs: remove redundant auto reclaim log message

Remove the log message before reclaiming a chunk in
btrfs_reclaim_bgs_work(). Especially with automatic block-group
reclaiming these messages spam the kernel log.

Note there is also a tracepoint for the same condition to ease debugging.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>