drm/amd/pp: Remove dead error checking code on Vega10

when smu failed, print out the error info immediately
for debug. smum_send_msg_to_smu always return true,
so no need to check return value.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>