cast to uint32_t to avoid compiler warning

that said, it's possible this api might return
a variety of non-zero codes.  code could benefit
from being updated (e.g., documenting return codes)

Author: henrygab

libraries/USBHost/examples/ADKTerminalTest/ADKTerminalTest.ino

@@ -37,7 +37,7 @@ void setup(void)
   while (!SERIAL_PORT_MONITOR); // Wait for serial port to connect - used on Leonardo, Teensy and other boards with built-in USB CDC serial connection
   SERIAL_PORT_MONITOR.println("\r\nADK demo start");
 
-  if (usb.Init() == -1)
+  if (usb.Init() == (uint32_t)-1)
 	SERIAL_PORT_MONITOR.println("OSC did not start.");
 
   delay(20);

libraries/USBHost/examples/KeyboardController/KeyboardController.ino

@@ -83,8 +83,7 @@ void setup()
 {
   SerialDebug.begin( 115200 );
   SerialDebug.println("USB Host Keyboard Controller Program started");
-
-  if (usb.Init() == -1)
+  if (usb.Init() == (uint32_t)-1)
 	  SerialDebug.println("USB Host did not start.");
 
   SerialDebug.println("USB Host started");

libraries/USBHost/examples/MouseController/MouseController.ino

@@ -91,7 +91,7 @@ void setup()
   SerialDebug.begin( 115200 );
   SerialDebug.println("USB Host Mouse Controller Program started");
 
-  if (usb.Init() == -1)
+  if (usb.Init() == (uint32_t)-1)
     SerialDebug.println("USB Host did not start.");
 
   SerialDebug.println("USB Host started");

libraries/USBHost/examples/USB_desc/USB_desc.ino

@@ -59,8 +59,8 @@ void setup()
   SerialDebug.println("Starting USB Descriptor test");
 
   SerialDebug.println("Initializing USB");
-  if (usb.Init() == -1)
-      SerialDebug.println("USBhost did not start.");
+  if (usb.Init() == (uint32_t)-1)
+    SerialDebug.println("USBhost did not start.");
 
   delay( 20 );
 
@@ -159,7 +159,7 @@ byte getdevdescr( byte addr, byte &num_conf )
   return( 0 );
 }
 
-void printhubdescr(uint8_t *descrptr, uint8_t addr)
+void printhubdescr(uint8_t *descrptr, __attribute__((unused)) uint8_t addr)
 {
     HubDescriptor  *pHub = (HubDescriptor*) descrptr;
     uint8_t        len = *((uint8_t*)descrptr);
@@ -213,13 +213,15 @@ byte getconfdescr( byte addr, byte conf )
   byte descr_length;
   byte descr_type;
   uint16_t total_length;
+  // BUGBUG -- no check of return code from usb.getConfDescr()
   rcode = usb.getConfDescr( addr, 0, 4, conf, buf );  //get total length
   LOBYTE( total_length ) = buf[ 2 ];
   HIBYTE( total_length ) = buf[ 3 ];
   if( total_length > sizeof(buf)) {    //check if total length is larger than buffer
     printProgStr(Conf_Trunc_str);
     total_length = sizeof(buf);
   }
+  // BUGBUG -- no check of return code from usb.getConfDescr()
   rcode = usb.getConfDescr( addr, 0, total_length, conf, buf ); //get the whole descriptor
   while( buf_ptr < buf + total_length ) {  //parsing descriptors
     descr_length = *( buf_ptr );