drm/amdgpu: fix error handling in amdgpu_vm_init

stable inclusion
from stable-v6.6.3
commit 5e94f18d5e93bd7c352e6bb7c04fbe3c4f44a6d6
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5e94f18d5e93bd7c352e6bb7c04fbe3c4f44a6d6



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commit 8473bfdcb5b1a32fd05629c4535ccacd73bc5567 upstream.

When clearing the root PD fails we need to properly release it again.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>