I've got to say, I'm pretty surprised at the responses I'm reading here... I thought this was a very common thing? I know I've heard it mentioned a few times around, it's kind of a famous thing that dog paws smell like crackers or Fritos. My chihuahua's feet have smelled like that a little. I assume it's just how their nails, pads or even feet-fur smells. I don't think it's anything to worry about at all. Now obviously, I'm not veterinarian, so I would hate to give out bad advice, you could ask your vet to be sure if it really concerns you. Mine has always been very healthy (according to the vet) and she eats well, and her paws have always smelled like that. My mom calls her "cracker paws" even sometimes!
I just checked my dog and her paws don't smell much like it now, I trim her toe-fur, which is a good practice anyway, and I don't feed her food with corn in it, so maybe that could be something for you to try.