It should be the first one, but in practice, both are actually fine. Lots of people would say the second one just as much, because it doesn't actually sound wrong.

The first one is correct, the second is incorrect. Seeing as soup is something that is uncountable, you have to specify with any or some, it shouldn't be left without these words.

In native conversation both are correct. On a test, "any soup" would be the answer I would use.

Answer is good