AP_HAL: remove buggy write implementation

libraries/AP_HAL/utility/BetterStream.cpp

@@ -15,16 +15,6 @@ void AP_HAL::BetterStream::vprintf(const char *fmt, va_list ap)
     print_vprintf(this, fmt, ap);
 }
 
-size_t AP_HAL::BetterStream::write(const uint8_t *buffer, size_t size)
-{
-    for (size_t i=0; i<size;i++) {
-        if (write(buffer[i] == 0)) {
-            return i;
-        }
-    };
-    return size;
-}
-
 size_t AP_HAL::BetterStream::write(const char *str)
 {
     return write((const uint8_t *)str, strlen(str));

libraries/AP_HAL/utility/BetterStream.h

@@ -34,7 +34,7 @@ public:
     void println(const char *str) { printf("%s\r\n", str); }
 
     virtual size_t write(uint8_t) = 0;
-    virtual size_t write(const uint8_t *buffer, size_t size);
+    virtual size_t write(const uint8_t *buffer, size_t size) = 0;
     size_t write(const char *str);
 
     virtual uint32_t available() = 0;