f2fs: fix to update new block address correctly for OPU

Previously, we allocated a new block address for OPU mode in direct_IO.

But the new address couldn't be assigned to @map->m_pblk correctly.

This patch fix it.

Cc: <stable@vger.kernel.org>
Fixes: 511f52d02f05 ("f2fs: allow out-place-update for direct IO in LFS mode")
Signed-off-by: Jia Zhu <zhujia13@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -1089,8 +1089,10 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 		if (test_opt(sbi, LFS) && flag == F2FS_GET_BLOCK_DIO &&
 							map->m_may_create) {
 			err = __allocate_data_block(&dn, map->m_seg_type);
-			if (!err)
+			if (!err) {
+				blkaddr = dn.data_blkaddr;
 				set_inode_flag(inode, FI_APPEND_WRITE);
+			}
 		}
 	} else {
 		if (create) {