Yeah, this is definitely Hinglish, but you do hear Indians using 'less' like this quite often.
that's true but this could just as easily be a comparative. as in, "there is less sugar in my tea (than in my coffee)"
It could also be "There is not (too) much sugar in my tea." "Too little" implies that the speaker would prefer more sugar, which is not necessarily the case.
I would only use less if I was comparing. Ex: There is less sugar in my tea than I would like. Is this sentence necessarily negative? What would you say if you are happy with just a little sugar in your tea?