internal/diff: add missing 'as' in comment

Change-Id: I40b9bc55744f6db5332d49dd47c8a4e409ecd9f3
GitHub-Last-Rev: c58c8ec
GitHub-Pull-Request: #63870
Reviewed-on: https://go-review.googlesource.com/c/go/+/538862
TryBot-Result: Gopher Robot <[email protected]>
Auto-Submit: Keith Randall <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Run-TryBot: qiulaidongfeng <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: qiulaidongfeng <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>

Author: callthingsoff

src/internal/diff/diff.go

@@ -74,7 +74,7 @@ func Diff(oldName string, old []byte, newName string, new []byte) []byte {
 			continue
 		}
 
-		// Expand matching lines as far possible,
+		// Expand matching lines as far as possible,
 		// establishing that x[start.x:end.x] == y[start.y:end.y].
 		// Note that on the first (or last) iteration we may (or definitely do)
 		// have an empty match: start.x==end.x and start.y==end.y.