ubi: Simplify bool conversion

mainline inclusion
from mainline-v6.4-rc1
commit ef503113
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9195H
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ef5031137b90c5338792f7073ba3bf38d14c8cf1



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./drivers/mtd/ubi/build.c:1261:33-38: WARNING: conversion to bool not needed here

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4061


Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>