I personally love
Harry for a boy and i would use it anyway despite HP - i think that it is quite a popular name anyway. In a way i think even though it is the main character in HP you would get less of an association than if you used a name like Albus or
Luna, because it is an 'ordinary' name. If you see what i mean? I say go for it :)
p.s my godbrother is called
Harry and he is the sweetest, kindest boy i have ever met so i have nothing but good associations with
Harry
p.p.s I love it as a nn for
Henry as well