ubifs: ubifs_dump_sleb: Remove unused function

mainline inclusion
from mainline-v5.11-rc1
commit bf6dab7a
category: bugfix
bugzilla: 182885 https://gitee.com/openeuler/kernel/issues/I4DDEL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bf6dab7a6ce79c56764623b970be10fc6edd8a68



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Function ubifs_dump_sleb() is defined but unused, it can be removed.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>