Print not aborting on write failure

See arduino#3614

Author: cmaglie

cores/arduino/Print.cpp

@@ -17,6 +17,7 @@
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  
  Modified 23 November 2006 by David A. Mellis
+ Modified 03 August 2015 by Chuck Todd
  */
 
 #include <stdlib.h>
@@ -34,7 +35,8 @@ size_t Print::write(const uint8_t *buffer, size_t size)
 {
   size_t n = 0;
   while (size--) {
-    n += write(*buffer++);
+    if (write(*buffer++)) n++;
+    else break;
   }
   return n;
 }