Update params.seed when -S is not given

[gpakosz]

This PR fixes the following use case

$ ./flux -d flux-klein-4b -p "Some random bug" -W 512 -H 512 -o output.png
...
Seed: 1770589003
...

$ ./flux -d flux-klein-4b -S 1770589003 -p "Some random bug" -W 512 -H 512 -o output.png

Generating different images.

[clort81]

The params.seed is the seed given to the program

        case 'S': params.seed = atoll(optarg); break;

the actual_seed is the seed actually used by the program.

Setting params.seed to the randomly generated seed has no effect. And makes no logical sense, since no seed was passed as a parameter.

I suggest closing this.

[Edit:] Sorry I hadn't looked into iris_cli. There i see
static int generate_image(....
params.seed = actual_seed;

Not sure about that cli stuff. Sorry for my comment, leaving it up though.