drm/amdgpu: fix non-pointer dereference for non-RAS supported

Backtrace on gpu recover test on Navi10.

[ 1324.516681] RIP: 0010:amdgpu_ras_set_error_query_ready+0x15/0x20 [amdgpu]
[ 1324.523778] Code: 4c 89 f7 e8 cd a2 a0 d8 e9 99 fe ff ff 45 31 ff e9 91 fe ff ff 0f 1f 44 00 00 55 48 85 ff 48 89 e5 74 0e 48 8b 87 d8 2b 01 00 <40> 88 b0 38 01 00 00 5d c3 66 90 0f 1f 44 00 00 55 31 c0 48 85 ff
[ 1324.543452] RSP: 0018:ffffaa1040e4bd28 EFLAGS: 00010286
[ 1324.549025] RAX: 0000000000000000 RBX: ffff911198b20000 RCX: 0000000000000000
[ 1324.556217] RDX: 00000000000c0a01 RSI: 0000000000000000 RDI: ffff911198b20000
[ 1324.563514] RBP: ffffaa1040e4bd28 R08: 0000000000001000 R09: ffff91119d0028c0
[ 1324.570804] R10: ffffffff9a606b40 R11: 0000000000000000 R12: 0000000000000000
[ 1324.578413] R13: ffffaa1040e4bd70 R14: ffff911198b20000 R15: 0000000000000000
[ 1324.586464] FS:  00007f4441cbf540(0000) GS:ffff91119ed80000(0000) knlGS:0000000000000000
[ 1324.595434] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1324.601345] CR2: 0000000000000138 CR3: 00000003fcdf8004 CR4: 00000000003606e0
[ 1324.608694] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1324.616303] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1324.623678] Call Trace:
[ 1324.626270]  amdgpu_device_gpu_recover+0x6e7/0xc50 [amdgpu]
[ 1324.632018]  ? seq_printf+0x4e/0x70
[ 1324.636652]  amdgpu_debugfs_gpu_recover+0x50/0x80 [amdgpu]
[ 1324.643371]  seq_read+0xda/0x420
[ 1324.647601]  full_proxy_read+0x5c/0x90
[ 1324.652426]  __vfs_read+0x1b/0x40
[ 1324.656734]  vfs_read+0x8e/0x130
[ 1324.660981]  ksys_read+0xa7/0xe0
[ 1324.665201]  __x64_sys_read+0x1a/0x20
[ 1324.669907]  do_syscall_64+0x57/0x1c0
[ 1324.674517]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1324.680654] RIP: 0033:0x7f44417cf081
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: John Clements <John.Clements@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c

@@ -82,13 +82,13 @@ static bool amdgpu_ras_check_bad_page(struct amdgpu_device *adev,
 
 void amdgpu_ras_set_error_query_ready(struct amdgpu_device *adev, bool ready)
 {
-	if (adev)
+	if (adev && amdgpu_ras_get_context(adev))
 		amdgpu_ras_get_context(adev)->error_query_ready = ready;
 }
 
 bool amdgpu_ras_get_error_query_ready(struct amdgpu_device *adev)
 {
-	if (adev)
+	if (adev && amdgpu_ras_get_context(adev))
 		return amdgpu_ras_get_context(adev)->error_query_ready;
 
 	return false;