As the crow flies not that far - but you'd have to walk the long way round - I'd say you're looking at a good 25-30 min walk (out Sheriff St away from town, then up East Road to the East Wall Road and then down to East Point) ... Really no quicker than getting off at Drumcondra and walking down Clonliffe Rd I wouldn't think (and the walk from Drumcondra is probalby more "scenic" )