Remove some warnings

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3992 42af7a65-404d-4744-a932-0658087f49c3

arch/sim/src/up_touchscreen.c

@@ -128,9 +128,6 @@ static int up_sample(FAR struct up_dev_s *priv,
                           FAR struct up_sample_s *sample);
 static int up_waitsample(FAR struct up_dev_s *priv,
                               FAR struct up_sample_s *sample);
-static int up_transfer(FAR struct up_dev_s *priv, uint8_t cmd);
-static void up_worker(FAR void *arg);
-static int up_interrupt(int irq, FAR void *context);
 
 /* Character driver methods */
 

arch/sim/src/up_x11eventloop.c

@@ -129,7 +129,7 @@ static void *up_x11eventthread(void *arg)
   if (ret != GrabSuccess)
     {
       fprintf(stderr, "Failed grap pointer\n");
-      return -1;
+      return NULL;
     }
 
   /* Then loop forever, waiting for events and processing events as they are