drm/amdgpu: Fixed bug on error when unloading amdgpu

drm/amdgpu: Fixed bug on error when unloading amdgpu

Fixed bug on error when unloading amdgpu.

The error message is as follows:
[  377.706202] kernel BUG at drivers/gpu/drm/drm_buddy.c:278!
[  377.706215] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  377.706222] CPU: 4 PID: 8610 Comm: modprobe Tainted: G          IOE      6.0.0-thomas #1
[  377.706231] Hardware name: ASUS System Product Name/PRIME Z390-A, BIOS 2004 11/02/2021
[  377.706238] RIP: 0010:drm_buddy_free_block+0x26/0x30 [drm_buddy]
[  377.706264] Code: 00 00 00 90 0f 1f 44 00 00 48 8b 0e 89 c8 25 00 0c 00 00 3d 00 04 00 00 75 10 48 8b 47 18 48 d3 e0 48 01 47 28 e9 fa fe ff ff <0f> 0b 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 54 55 48 89 f5 53
[  377.706282] RSP: 0018:ffffad2dc4683cb8 EFLAGS: 00010287
[  377.706289] RAX: 0000000000000000 RBX: ffff8b1743bd5138 RCX: 0000000000000000
[  377.706297] RDX: ffff8b1743bd5160 RSI: ffff8b1743bd5c78 RDI: ffff8b16d1b25f70
[  377.706304] RBP: ffff8b1743bd59e0 R08: 0000000000000001 R09: 0000000000000001
[  377.706311] R10: ffff8b16c8572400 R11: ffffad2dc4683cf0 R12: ffff8b16d1b25f70
[  377.706318] R13: ffff8b16d1b25fd0 R14: ffff8b1743bd59c0 R15: ffff8b16d1b25f70
[  377.706325] FS:  00007fec56c72c40(0000) GS:ffff8b1836500000(0000) knlGS:0000000000000000
[  377.706334] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  377.706340] CR2: 00007f9b88c1ba50 CR3: 0000000110450004 CR4: 00000000003706e0
[  377.706347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  377.706354] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  377.706361] Call Trace:
[  377.706365]  <TASK>
[  377.706369]  drm_buddy_free_list+0x2a/0x60 [drm_buddy]
[  377.706376]  amdgpu_vram_mgr_fini+0xea/0x180 [amdgpu]
[  377.706572]  amdgpu_ttm_fini+0x12e/0x1a0 [amdgpu]
[  377.706650]  amdgpu_bo_fini+0x22/0x90 [amdgpu]
[  377.706727]  gmc_v11_0_sw_fini+0x26/0x30 [amdgpu]
[  377.706821]  amdgpu_device_fini_sw+0xa1/0x3c0 [amdgpu]
[  377.706897]  amdgpu_driver_release_kms+0x12/0x30 [amdgpu]
[  377.706975]  drm_dev_release+0x20/0x40 [drm]
[  377.707006]  release_nodes+0x35/0xb0
[  377.707014]  devres_release_all+0x8b/0xc0
[  377.707020]  device_unbind_cleanup+0xe/0x70
[  377.707027]  device_release_driver_internal+0xee/0x160
[  377.707033]  driver_detach+0x44/0x90
[  377.707039]  bus_remove_driver+0x55/0xe0
[  377.707045]  pci_unregister_driver+0x3b/0x90
[  377.707052]  amdgpu_exit+0x11/0x6c [amdgpu]
[  377.707194]  __x64_sys_delete_module+0x142/0x2b0
[  377.707201]  ? fpregs_assert_state_consistent+0x22/0x50
[  377.707208]  ? exit_to_user_mode_prepare+0x3e/0x190
[  377.707215]  do_syscall_64+0x38/0x90
[  377.707221]  entry_SYSCALL_64_after_hwframe+0x63/0xcd

Signed-off-by: YiPeng Chai <YiPeng.Chai@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org