drm/amdkfd: remove unnecessary warning message on gpu reset

In XGMI configuration, more than one asic can be reset at same time,
kfd is able to handle this and no need to trigger the warning

Signed-off-by: shaoyunl <shaoyun.liu@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>