drm/amdgpu:fix vf_error_put

1,it should not work on non-SR-IOV case
2,the NO_VBIOS error is incorrect, should
handle it under detect_sriov_bios.
3,wrap the whole detect_sriov_bios with sriov check

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