drm/amdgpu/gfx11: unlock on error in gfx_v11_0_kiq_resume()

Add a missing amdgpu_bo_unreserve(ring->mqd_obj) to an error path in
gfx_v11_0_kiq_resume().

Fixes: 3d879e81 ("drm/amdgpu: add init support for GFX11 (v2)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>