std/math/big: minor documentation fix

std/math/big/worddiv.jule

@@ -602,7 +602,7 @@ fn divLargeW(mut &z: []Word, mut &u: []Word, uIn: []Word, vIn: []Word) {
 
 	// Scale the inputs so vIn's top bit is 1 (see “Scaling Inputs” above).
 	// vIn is treated as a read-only input (it may be in use by another
-	// goroutine), so we must make a copy.
+	// thread), so we must make a copy.
 	// uIn is copied to u.
 	shift := nlz(vIn[n-1])
 	mut v := getW(n)