lkl: posix-host: Fix -Wcast-function-type

lib/posix-host.c:189:49: warning: cast between incompatible function
    types from ‘void (*)(void *)’ to ‘void * (*)(void *)’
    [-Wcast-function-type]

lib/posix-host.c:270:28: warning: cast between incompatible function
   types from ‘void (*)(void *)’ to ‘void (*)(union sigval)’
   [-Wcast-function-type]

Signed-off-by: Andreas Gnau <rondom@rondom.de>

tools/lkl/lib/posix-host.c

@@ -186,7 +186,7 @@ static void mutex_free(struct lkl_mutex *_mutex)
 static lkl_thread_t thread_create(void (*fn)(void *), void *arg)
 {
 	pthread_t thread;
-	if (WARN_PTHREAD(pthread_create(&thread, NULL, (void* (*)(void *))fn, arg)))
+	if (WARN_PTHREAD(pthread_create(&thread, NULL, (void *)fn, arg)))
 		return 0;
 	else
 		return (lkl_thread_t) thread;
@@ -267,7 +267,7 @@ static void *timer_alloc(void (*fn)(void *), void *arg)
 		.sigev_value = {
 			.sival_ptr = arg,
 		},
-		.sigev_notify_function = (void (*)(union sigval))fn,
+		.sigev_notify_function = (void (*)())fn,
 	};
 
 	err = timer_create(CLOCK_REALTIME, &se, &timer);