nilfs2: hide nilfs_mdt_clear calls in nilfs_mdt_destroy

This will hide a function call of nilfs_mdt_clear() in
nilfs_mdt_destroy().

This ensures nilfs_mdt_destroy() to do cleanup jobs included in
nilfs_mdt_clear().

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/recovery.c

@@ -770,14 +770,8 @@ int nilfs_recover_logical_segments(struct the_nilfs *nilfs,
 		nilfs_finish_roll_forward(nilfs, sbi, ri);
 	}
 
-	nilfs_detach_checkpoint(sbi);
-	return 0;
-
  failed:
 	nilfs_detach_checkpoint(sbi);
-	nilfs_mdt_clear(nilfs->ns_cpfile);
-	nilfs_mdt_clear(nilfs->ns_sufile);
-	nilfs_mdt_clear(nilfs->ns_dat);
 	return err;
 }