UBI: Fastmap: Remove unnecessary `\'

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Git-commit: a18fd672675f50c1a05f8c6c03b9a34ef4f07cae
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Nikhilesh Reddy <reddyn@codeaurora.org>