Yes you can eat the white stuff that is on your salmon.
The white stuff that comes out of your salmon is actually just coagulated protein which is very safe to eat and actually when you do eat that white stuff from the salmon your health will benefit because you'll be getting protein in your body which is healthy for you.
The salmon produces the white stuff because when the salmon cooks the muscle fibers of the salmon contract, causing it to wring out the fish's internal protein, or albumin.
The white stuff in the salmon is healthy and okay to eat.
But you can remove it if you don't want to eat it.
However I've always just eaten the white stuff along with the salmon.