drm/amdgpu: Fix RAS function interface

The correctable and uncorrectable errors
are calculated at each invocation of this
function. Therefore, it is highly inefficient to
return just one of them based on a Boolean
input. If the caller wants both, twice the work
would be done. (And this work is O(n^3) on
Vega20.)

Fix this "interface" to simply return what it had
calculated--both values. Let the caller choose
what it wants to record, inspect, use.

Cc: Alexander Deucher <Alexander.Deucher@amd.com>
Cc: John Clements <john.clements@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Alexander Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>