drm/panfrost: Put mapping instead of shmem obj on panfrost_mmu_map_fault_addr() error

stable inclusion
from stable-v5.10.132
commit 2e760fe05d3ea5b5addb02691ec8a29e601dff56
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5YS3T

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2e760fe05d3ea5b5addb02691ec8a29e601dff56



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commit fb6e0637 upstream.

When panfrost_mmu_map_fault_addr() fails, the BO's mapping should be
unreferenced and not the shmem object which backs the mapping.

Cc: stable@vger.kernel.org
Fixes: bdefca2d ("drm/panfrost: Add the panfrost_gem_mapping concept")
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220630200601.1884120-2-dmitry.osipenko@collabora.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>