f2fs: avoid infinite loop at cp_error

This patch avoids an infinite loop in sync_dirty_inode_page when -EIO was
detected.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/checkpoint.c

@@ -731,6 +731,9 @@ void sync_dirty_dir_inodes(struct f2fs_sb_info *sbi)
 	struct dir_inode_entry *entry;
 	struct inode *inode;
 retry:
+	if (unlikely(f2fs_cp_error(sbi)))
+		return;
+
 	spin_lock(&sbi->dir_inode_lock);
 
 	head = &sbi->dir_inode_list;