drm/amdgpu: drop non-necessary call trace dump

This extra call trace dump comes out in every gpu reset.
And it gives people a wrong impression that something
went wrong. Although actually there was not.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>