btrfs: remove fs_info argument from priority_reclaim_metadata_space()

btrfs: remove fs_info argument from priority_reclaim_metadata_space()

We don't need it since we can grab fs_info from the given space_info.
So remove the fs_info argument.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <asj@kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>