drm/amdgpu: fix mmhub client id out-of-bounds access

Properly handle cid 0x140.

Fixes: aba2be41470a ("drm/amdgpu: add mmhub 3.3.0 support")
Signed-off-by: Lang Yu <Lang.Yu@amd.com>
Reviewed-by: Yifan Zhang <yifan1.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v3_3.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v3_3.c
index b396196..238ea40 100644
--- a/drivers/gpu/drm/amd/amdgpu/mmhub_v3_3.c
+++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v3_3.c
@@ -99,16 +99,15 @@
 	switch (amdgpu_ip_version(adev, MMHUB_HWIP, 0)) {
 	case IP_VERSION(3, 3, 0):
 	case IP_VERSION(3, 3, 1):
-		mmhub_cid = mmhub_client_ids_v3_3[cid][rw];
+		mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_v3_3) ?
+			    mmhub_client_ids_v3_3[cid][rw] :
+			    cid == 0x140 ? "UMSCH" : NULL;
 		break;
 	default:
 		mmhub_cid = NULL;
 		break;
 	}
 
-	if (!mmhub_cid && cid == 0x140)
-		mmhub_cid = "UMSCH";
-
 	dev_err(adev->dev, "\t Faulty UTCL2 client ID: %s (0x%x)\n",
 		mmhub_cid ? mmhub_cid : "unknown", cid);
 	dev_err(adev->dev, "\t MORE_FAULTS: 0x%lx\n",