Preheat oven to 450 degrees. Place salmon on a rimmed baking sheet; season with salt. Roast until opaque throughout, about 15 minutes. Meanwhile, in a small saucepan, melt butter over medium. Add flour and cook, whisking, 1 minute. Add wine and bring to a boil; reduce to a simmer, and cook until liquid is reduced by half, 8 to 10 minutes. Stir in chives; season with salt and pepper. With a fork, gently break salmon into large chunks and serve topped with white-wine sauce.