The short answer to whether or not intelligence is affected by a better sense of smell is no, but the one thing you can say about evolution is that it trends towards efficiency and the question must be asked whether you need great vision AND great olfactory senses AND intelligence.
The brain (depending on the scientific paper you read) uses around 20% - 25% of the body's energy every day. That means that it's a massive energy sink that has to provide a substantial benefit to us to make up for that energy cost; and it does. It originally made us better hunters, more efficient with the resources around us, then better at building and refining tools that we use to achieve our ends.
Our five senses are in essence a part of our nervous system and provide key inputs to the brain. That sensory input also costs energy to sustain. I don't have exact figures on how much that cost is exactly, but there is a cost just the same. So the question becomes whether or not the development of an advanced brain is necessary if the combination of heightened visual and olfactory senses already make us better gatherers and more adept at avoiding danger.
Of course, there is another consideration here. Most evolutionary biologists believe now that the brain development in humans was only possible after the introduction of some meat into their diet. There are certain nutrients that proto-humans could not get from fruit and vegetables alone, and that the introduction of small amounts of meat, that transition into an omnivorous organism, was a key component of the development of modern human intelligence.
If that is the case, then it's arguable that heightened olfactory and visual senses has made your proto-humans adept in their environment; being able to forage and avoid danger sufficiently that the further investment in neural advancement (especially without the key nutrients provided by meat) may never happen.
Of course, the other consideration here is that most anthropologists believe that while we had the capacity for intelligence for many millennia before we actually started using it, the manifestation was brought on by our control of fire. Before that, we spent all our time surviving. After we harnessed fire we could sit around one, relatively safe from predators, and spend time actually thinking.
In other words, being capable of intelligence is not the same as having it.
What all this means for your proto-human stock is that by giving them a better sense of smell, you don't necessarily deprive them of intelligence, but you do very much change the priorities which evolution would apply to humans as improvements, and you also change their preferred environment to such an extent that two key contributors to the development of human intelligence (meat and fire) may not occur.