Merge pull request #10964 from c1728p9/greentea_error

Add newline after mbed error so greentea shows it

Author: 0xc0170

platform/mbed_error.c

@@ -125,6 +125,8 @@ WEAK MBED_NORETURN void error(const char *format, ...)
         va_start(arg, format);
         mbed_error_vprintf(format, arg);
         va_end(arg);
+        // Add a newline to prevent any line buffering
+        mbed_error_puts("\n");
 #endif
     }