Fix: remove filename prefix for reducehashranges

[Banh-Canh]

Hello, just fixing a small mistake of mine from #14332.

About adding the dimensions as a prefix for textures using a non-default reducehashvalue:
It was because I thought multiple differents reducehash value could create a mess with other textures that use the other values but it doesn't look like it.

I tried to be safe but I now realize that this way [reducehashranges] does not work with [hashes] (unless some changes are made) or at least, isn't intuitive since this won't work:

[hashes]
128x256_addresscluthash = images1.png

but this works (even though the dumped file is still named with the prefix):

[hashes]
addresscluthash = images1.png

So to correct my mistake (sorry), I simply removed the prefix I previously added which should fix that.

[reducehashranges]
;; doesn't do anything unless reduceHash = true
;; syntax : w,h = reducehashvalue
128,256 = 0.3125
[hashes]
;; dumped file using the reducehash value, the following still work and is coherent with the filename
addresscluthash = images1.png

Filenames will be back to: addresscluthash.png
Like all the others.

Double-checked how it would interact with [hashranges] and it looks ok (I don't think anyone is going to be using both though).

[hrydgard]

ok, that makes sense.