revert 6630fe7 availableForWrite() return int

Author: hathach

cores/arduino/Print.h

@@ -58,7 +58,7 @@ class Print
 
     // default to zero, meaning "a single write may block"
     // should be overriden by subclasses with buffering
-    virtual size_t availableForWrite() { return 0; }
+    virtual int availableForWrite() { return 0; }
 
     size_t print(const __FlashStringHelper *);
     size_t print(const String &);

cores/arduino/TinyUSB/Adafruit_TinyUSB_ArduinoCore

@@ -160,7 +160,7 @@ int Serial_::available(void)
 	return usb.available(CDC_ENDPOINT_OUT);
 }
 
-size_t Serial_::availableForWrite(void)
+int Serial_::availableForWrite(void)
 {
 	// return the number of bytes left in the current bank,
 	// always EP size - 1, because bank is flushed on every write

cores/arduino/USB/CDC.cpp

@@ -129,7 +129,7 @@ class Serial_ : public Stream
 	void end(void);
 
 	virtual int available(void);
-	virtual size_t availableForWrite(void);
+	virtual int availableForWrite(void);
 	virtual int peek(void);
 	virtual int read(void);
 	virtual void flush(void);

cores/arduino/USB/USBAPI.h

@@ -131,7 +131,7 @@ int Uart::available()
   return rxBuffer.available();
 }
 
-size_t Uart::availableForWrite()
+int Uart::availableForWrite()
 {
   return txBuffer.availableForStore();
 }

cores/arduino/Uart.cpp

@@ -33,7 +33,7 @@ class Uart : public HardwareSerial
     void begin(unsigned long baudrate, uint16_t config);
     void end();
     int available();
-    size_t availableForWrite();
+    int availableForWrite();
     int peek();
     int read();
     void flush();