I don't think you can remove the smell, it might be best to throw those ones out and start again.
You have added a lot of bicarbonate for the amount of chickpeas. Recipes that include bicarbonate generally seem to go with a half teaspoon per pound (roughly 2.5 g per 450 grams), not 2 teaspoons per 400 g.
There is generally no need to soften them with bicarbonate at all. A gentle boil or simmer for an hour or two is usually sufficient to cook them completely after an overnight soak.
If you wished to cook them in the curry, leave the salt out until the chickpeas are cooked or close to cooked. Adding salt (or at least calcium and magnesium salts, which are part of sea-salt) tend to harden the chickpeas so that they don't soften as easily. With added salt, they should still cook but it will generally take longer to do so. Though apparently soaking in salt water can soften beans more readily according to this Cooking SE page.
According to the FAQ on the site HeyNutritionLady.com, the causes of hard beans are not usually related to cooking, but rather to age of the beans. Apparently soaking only reduces stove-top cooking time by about 10 minutes, but can remove things from the chickpeas that cause gas and bloating in some people. They also say that hard water (high calcium content) can also cause the chickpeas to harden when cooking - bicarbonate can lower this, but you shouldn't need much.