f2fs: fix an error return value in truncate_partial_data_page

This patch fix a error return value in truncate_partial_data_page
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -528,7 +528,7 @@ static int truncate_partial_data_page(struct inode *inode, u64 from,
 
 	page = get_lock_data_page(inode, index, true);
 	if (IS_ERR(page))
-		return 0;
+		return PTR_ERR(page) == -ENOENT ? 0 : PTR_ERR(page);
 truncate_out:
 	f2fs_wait_on_page_writeback(page, DATA, true);
 	zero_user(page, offset, PAGE_SIZE - offset);