usb dont spawn worker process, because only one USB controller is supported

usb/usb.c

@@ -8,17 +8,7 @@
 #include <string.h>
 #include <system.h>
 
-static void usb_poll_driver_proc (void* arg) {
+static void usb_poll_driver_proc (void* arg) { struct device_info* info = arg; }
-  struct device_info* info = arg;
-
-  mprintf ("Polling device %s\n", info->key);
-
-  for (;;) {
-    device_do (info->key, XUSBCTRL_POLL_DRIVER, NULL, NULL, NULL, NULL);
-
-    sched ();
-  }
-}
 
 void app_main (void) {
   libprocess_self_init ();
@@ -44,13 +34,14 @@ void app_main (void) {
         continue;
       }
 
-      struct process_data* pdata = process_spawn (&usb_poll_driver_proc, info);
+      mprintf ("Polling device %s\n", info->key);
 
-      mprintf ("Started USB poller process: PID %d\n", pdata->pid);
+      for (;;) {
+        device_do (info->key, XUSBCTRL_POLL_DRIVER, NULL, NULL, NULL, NULL);
+
+        sched ();
+      }
     }
-
-    for (;;)
-      ;
   } else {
     mprintf ("ERROR unknown command %s\n", commandbuf);
   }