drm/admgpu: replace kmalloc() and memcpy() with kmemdup()

The static analyser tool gave the following advice:

./drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c:1266:7-14: WARNING opportunity for kmemdup

 → 1266         tmp = kmalloc(used_size, GFP_KERNEL);
   1267         if (!tmp)
   1268                 return -ENOMEM;
   1269
 → 1270         memcpy(tmp, &host_telemetry->body.error_count, used_size);

Replacing kmalloc() + memcpy() with kmemdump() doesn't change semantics.
Original code works without fault, so this is not a bug fix but proposed improvement.

Link: https://lwn.net/Articles/198928/
Fixes: 84a2947 ("drm/amdgpu: Implement virt req_ras_err_count")
Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: Xinhui Pan <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Simona Vetter <[email protected]>
Cc: Zhigang Luo <[email protected]>
Cc: Victor Skvortsov <[email protected]>
Cc: Hawking Zhang <[email protected]>
Cc: Lijo Lazar <[email protected]>
Cc: Yunxiang Li <[email protected]>
Cc: Jack Xiao <[email protected]>
Cc: Vignesh Chander <[email protected]>
Cc: Danijel Slivka <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Reviewed-by: Lijo Lazar <[email protected]>
Signed-off-by: Mirsad Todorovac <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Mirsad Todorovac

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

@@ -1263,12 +1263,10 @@ static int amdgpu_virt_cache_host_error_counts(struct amdgpu_device *adev,
 	if (used_size > (AMD_SRIOV_RAS_TELEMETRY_SIZE_KB << 10))
 		return 0;
 
-	tmp = kmalloc(used_size, GFP_KERNEL);
+	tmp = kmemdup(&host_telemetry->body.error_count, used_size, GFP_KERNEL);
 	if (!tmp)
 		return -ENOMEM;
 
-	memcpy(tmp, &host_telemetry->body.error_count, used_size);
-
 	if (checksum != amd_sriov_msg_checksum(tmp, used_size, 0, 0))
 		goto out;