drm/amdgpu: fail if no buffer object handle chunk provided
If an AMDGPU_CCMD_CS_SUBMIT request has a nonzero bo_count but no AMDGPU_CHUNK_ID_BO_HANDLES chunk, the code that prints an error if the submit ioctl failed would suffer a null pointer dereference.
Signed-off-by: Demi Marie Obenour demi@invisiblethingslab.com