Correct write size

ttynvt_write() must on succesful writes return the number of bytes
written.

telnet_tx() always returns 0 (implicitly assuming srv_write() always
succeeds).

ttynvt.c

@@ -449,13 +449,15 @@ ttynvt_write(fuse_req_t req, const char *data, size_t size, off_t off,
         fuse_reply_err(req, EPIPE);
         return;
     }
+#if 0
     else if (res == 0)
     {
         fuse_reply_err(req, EAGAIN);
         return;
     }
+#endif
 
-    fuse_reply_write(req, res);
+    fuse_reply_write(req, size);
 }
 
 static int baudrate(speed_t speed)