scanner_test: fix using end_of_text

vlib/toml/scanner/scanner_test.v

@@ -25,9 +25,9 @@ fn test_next() {
 	assert s.next() == `a`
 	assert s.next() == `b`
 	assert s.next() == `c`
-	assert s.next() == -1
-	assert s.next() == -1
-	assert s.next() == -1
+	assert s.next() == scanner.end_of_text
+	assert s.next() == scanner.end_of_text
+	assert s.next() == scanner.end_of_text
 }
 
 fn test_skip() {
@@ -35,14 +35,14 @@ fn test_skip() {
 	assert s.next() == `a`
 	s.skip()
 	assert s.next() == `c`
-	assert s.next() == -1
+	assert s.next() == scanner.end_of_text
 }
 
 fn test_skip_n() {
 	mut s := scanner.new_scanner(input: scan_input) or { panic(err) }
 	s.skip_n(2)
 	assert s.next() == `c`
-	assert s.next() == -1
+	assert s.next() == scanner.end_of_text
 }
 
 fn test_at() {
@@ -54,7 +54,7 @@ fn test_at() {
 	assert s.next() == `a`
 	assert s.next() == `b`
 	assert s.next() == `c`
-	assert s.next() == -1
+	assert s.next() == scanner.end_of_text
 }
 
 fn test_peek() {
@@ -62,13 +62,13 @@ fn test_peek() {
 	assert s.peek(0) == `a`
 	assert s.peek(1) == `b`
 	assert s.peek(2) == `c`
-	assert s.peek(3) == -1
-	assert s.peek(4) == -1
+	assert s.peek(3) == scanner.end_of_text
+	assert s.peek(4) == scanner.end_of_text
 	//
 	assert s.next() == `a`
 	assert s.next() == `b`
 	assert s.next() == `c`
-	assert s.next() == -1
+	assert s.next() == scanner.end_of_text
 }
 
 fn test_reset() {
@@ -76,7 +76,7 @@ fn test_reset() {
 	assert s.next() == `a`
 	s.next()
 	s.next()
-	assert s.next() == -1
+	assert s.next() == scanner.end_of_text
 	s.reset()
 	assert s.next() == `a`
 }