plane_info is not a typical array, the data is not contiguous:
pinfo = (void *)pinfo + sizeof(*constr) * num_planes +
2 * sizeof(u32);
Replace the single element array with a single element field.
This fixes the following cocci warning:
drivers/media/platform/qcom/venus/hfi_helper.h:1009:36-46: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)