realloc_sg_buffer
status_t realloc_sg_buffer(sg_buffer *sgb, size_t size);
if(B_OK == realloc_sg_buffer(&sgb_own, sgb_len)){
if( B_OK != realloc_sg_buffer(sgb, ccbio->cam_dxfer_len + 4)){ /* TODO: 4 - hardcoded? */