btrfs: cleanup, remove stray return statements

Signed-off-by: David Sterba <[e-mail]>

fs/btrfs/disk-io.c

···
 		balance_dirty_pages_ratelimited(
 				   root->fs_info->btree_inode->i_mapping);
 	}
-	return;
 }
 
 void btrfs_btree_balance_dirty(struct btrfs_root *root)

fs/btrfs/inode.c

···
 no_delete:
 	btrfs_remove_delayed_node(inode);
 	clear_inode(inode);
-	return;
 }
 
 /*

fs/btrfs/locking.c

···
 		atomic_dec(&eb->spinning_readers);
 		read_unlock(&eb->lock);
 	}
-	return;
 }
 
 /*
···
 		    waitqueue_active(&eb->read_lock_wq))
 			wake_up(&eb->read_lock_wq);
 	}
-	return;
 }
 
 /*

fs/btrfs/raid56.c

···
 	}
 
 	spin_unlock_irqrestore(&table->cache_lock, flags);
-	return;
 }
 
 /*
···
 		err = -EIO;
 
 	rbio_orig_end_io(rbio, err);
-	return;
 }
 
 /*

fs/btrfs/scrub.c

···
 
 	if (sblock->no_io_error_seen)
 		scrub_recheck_block_checksum(sblock);
-
-	return;
 }
 
 static inline int scrub_check_fsid(u8 fsid[],

fs/btrfs/volumes.c

···
 		return;
 	file_update_time(filp);
 	filp_close(filp, NULL);
-	return;
 }
 
 static int btrfs_rm_dev_item(struct btrfs_root *root,