jfs: Remove check for PageUptodate

Pages returned from read_mapping_page() are always uptodate, so
this check is unnecessary.

Signed-off-by: Matthew Wilcox (Oracle) <[e-mail]>

fs/jfs/jfs_metapage.c

···
 		SetPageUptodate(page);
 	} else {
 		page = read_mapping_page(mapping, page_index, NULL);
-		if (IS_ERR(page) || !PageUptodate(page)) {
+		if (IS_ERR(page)) {
 			jfs_err("read_mapping_page failed!");
 			return NULL;
 		}