Looks "cold" across the top, you can still see the clean edges of the fender and the patch in some places. I like to see more penetration than that myself. Sheet metal is tough because you don't want to warp it, but you'll be grinding the outside weld off so you want to be sure its welded all the way through.
Its not structural, but if there was any less penetration I'd say you'd have to go over it some. Since the fender is off the car, you could try welding on the backside to touch it up a little.
