blkcg, writeback: Rename wbc_account_io() to wbc_account_cgroup_owner()

wbc_account_io() does a very specific job - try to see which cgroup is
actually dirtying an inode and transfer its ownership to the majority
dirtier if needed.  The name is too generic and confusing.  Let's
rename it to something more specific.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index eda4181..e1cab17 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -470,7 +470,7 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 	}
 
 	if (fio->io_wbc && !is_read_io(fio->op))
-		wbc_account_io(fio->io_wbc, page, PAGE_SIZE);
+		wbc_account_cgroup_owner(fio->io_wbc, page, PAGE_SIZE);
 
 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
 
@@ -537,7 +537,7 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 	}
 
 	if (fio->io_wbc)
-		wbc_account_io(fio->io_wbc, bio_page, PAGE_SIZE);
+		wbc_account_cgroup_owner(fio->io_wbc, bio_page, PAGE_SIZE);
 
 	io->last_block_in_bio = fio->new_blkaddr;
 	f2fs_trace_ios(fio, 0);