drm/nouveau: Fix a potential theorical leak in nouveau_get_backlight_name()

stable inclusion
from stable-v5.10.117
commit 9e40f2c513926371b30eebb14e5648378d11ba2e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L66B

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9e40f2c513926371b30eebb14e5648378d11ba2e



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[ Upstream commit ab244be4 ]

If successful ida_simple_get() calls are not undone when needed, some
additional memory may be allocated and wasted.

Here, an ID between 0 and MAX_INT is required. If this ID is >=100, it is
not taken into account and is wasted. It should be released.

Instead of calling ida_simple_remove(), take advantage of the 'max'
parameter to require the ID not to be too big. Should it be too big, it
is not allocated and don't need to be freed.

While at it, use ida_alloc_xxx()/ida_free() instead to
ida_simple_get()/ida_simple_remove().
The latter is deprecated and more verbose.

Fixes: db1a0ae2 ("drm/nouveau/bl: Assign different names to interfaces")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[Fixed formatting warning from checkpatch]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/9ba85bca59df6813dc029e743a836451d5173221.1644386541.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>