fix the word counter example

examples/word_counter/word_counter.v

@@ -9,18 +9,15 @@ fn main() {
 	else {
 		path = os.args[1]
 	}
-	lines := os.read_file_lines(path.trim_space())
+	contents := os.read_file(path.trim_space())
 	mut m := map[string]int{}
-	for line in lines {
+	for word in contents.to_lower().split(' ') {
-		words := line.to_lower().split(' ')
-		for word in words {
 		key := filter_word(word)
 		if key == '' {
 			continue
 		}
 		m[key] = m[key] + 1// TODO m[key]++
 	}
-	}
 	// Sort the keys
 	mut keys := []string
 	for e in m.entries {