examples: no longer use printf in the coroutines example

Author: medvednikov

examples/coroutines/simple_coroutines.v

@@ -8,17 +8,17 @@ import net.http
 
 fn foo(a int) {
 	for {
-		// println('hello from foo()') // a=${a}')
-		C.printf(c'hello from foo() a=%d\n', a)
+		println('1hello from foo() a=${a}')
+		//C.printf(c'hello from foo() a=%d\n', a)
 		coroutines.sleep(1 * time.second)
 	}
 }
 
 fn foo2(a int) {
 	mut i := 0
 	for {
-		// println('hello from foo2()') // a=${a}')
-		C.printf(c'hello from foo2() a=%d\n', a)
+		println('hello from foo2() a=${a}')
+		//C.printf(c'hello from foo2() a=%d\n', a)
 		coroutines.sleep(2 * time.second)
 		i++
 		// resp := http.get('https://vlang.io/utc_now') or { panic(err) }
@@ -32,16 +32,16 @@ fn foo2(a int) {
 
 fn foo3(a int) {
 	for {
-		// println('hello from foo3()') // a=${a}')
-		C.printf(c'hello from foo3() a=%d\n', a)
+		 println('hello from foo3() a=${a}')
+		//C.printf(c'hello from foo3() a=%d\n', a)
 		coroutines.sleep(3 * time.second)
 	}
 }
 
 fn foo4(a int) {
 	for {
-		// println('hello from foo4()') // a=${a}')
-		C.printf(c'hello from foo4() a=%d\n', a)
+		println('hello from foo4() a=${a}')
+		//C.printf(c'hello from foo4() a=%d\n', a)
 		coroutines.sleep(3 * time.second)
 	}
 }