Well, probably not the same in Old Norse. "Jórr" isn't attested as a word for 'wild boar', it's a reconstructed Old West Norse word, because it fell out of use around the Viking Age. It did persist as a prefix in some personal names documented on rune stones (See Runnamnslexikon,2007, p141). It's more likely then it'd be "jór" as in a poetic word for horse. "Vík" on the other hand means "bay" or "inlet". Your link says it means "creek" in this context but I don't find that meaning in the Old Norse dictionaries I have on hand at the moment (e.g. Fritzner's Norrøn ordbok). If it's attested it's certainly the far less common meaning. "Vik" is the word for "bay" in all Scandinavian languages to this day.

So in other words something like "Stallion bay" would seem more likely. One might object that that interpretation makes no sense for an inland city that's not even on the bay of a lake, but that brings me to the point and answer of the question, which is that the name doesn't need to make sense. It wasn't meant to make sense, it was meant to approximate the original name, since the Vikings who came along couldn't pronounce Anglo-Saxon, and the Anglo-Saxons couldn't pronounce Latin.

Another example is Jórsalir, the Viking name for Jerusalem, which also uses "Jór-", combined with 'salr' (large room, hall) - the latter being a fairly common element in Scandinavian place names (e.g. Uppsala, Odensala, Sala). Anyway, since it's a completely unrelated language it has no shared etymology or meaning of the Semitic Yerushalem. It's simply an approximation in phonemes that the Norsemen could pronounce (and remember).

Back to Britain and you have the reverse as well: "Swansea" is near the sea but has nothing to do with swans. It's likely from Norse "Sveinsey" (Sven's island), adapted to English pronunciation.

Sometimes words got accidentally semi-translated, Old Norse "vindauga" became "window". 'Vind' does mean 'wind' but 'ow' is just an approximation of 'au[ga]' meaning 'eye'.

As your example shows, too, place names can be very interesting to linguists, anthropologists and historians, because they can tell the history of a place, and preserve old words and language. Because when names don't make sense, they tend to become "fossilized" (actual term) and don't evolve with the rest of the language. For instance, Old Norse "kaupangr" (town/marketplace) became Danish "købing" and Swedish "köping" where the 'au' diphthong turned into 'ø' among other changes. (the aforementioned 'auga' is now 'öga' in Swedish) In Finnish, which borrowed the word, it's still there - "kaupunki", even though Finnish has the 'ø' sound and would be capable of pronouncing the younger form. (Finnish did not have the 'g' sound, however, so it became 'k') So this tells us both something about Old Norse, but also about the history of contact between the Finns and their Scandinavian neighbors. Finnish even preserves some words older than Icelandic, like 'juusto' (cheese), related to Scandinavian 'ost(r)' but that initial 'j' was dropped when Proto-Norse became Old Norse. That is, it was borrowed as far back as before the Viking Age. (and likewise I could give examples where Swedish preserves older Finnish)

Anyway, the short answer was just 'One named turned into another so that they could pronounce it' .