Move flush() back to Stream::flush

flush is an operation on output, not input.

Author: eric-wieser

hardware/arduino/avr/cores/arduino/IStream.h

@@ -58,7 +58,6 @@ class IStream
     virtual int available() = 0;
     virtual int read() = 0;
     virtual int peek() = 0;
-    virtual void flush() = 0;
 
     IStream() {_timeout=1000;}
 

hardware/arduino/avr/cores/arduino/Stream.h

@@ -26,6 +26,8 @@
 
 class Stream : public Print, public IStream
 {
+public:
+  virtual void flush() = 0;
 };
 
 #endif

hardware/arduino/sam/cores/arduino/IStream.h

@@ -58,7 +58,6 @@ class IStream
     virtual int available() = 0;
     virtual int read() = 0;
     virtual int peek() = 0;
-    virtual void flush() = 0;
 
     IStream() {_timeout=1000;}
 

hardware/arduino/sam/cores/arduino/Stream.h

@@ -26,6 +26,8 @@
 
 class Stream : public Print, public IStream
 {
+public:
+  virtual void flush() = 0;
 };
 
 #endif