fifo: ignore error ECOMM only on Cygwin (fix compilaton on FreeBSD)

src/plugins/fifo/fifo.c

@@ -357,7 +357,11 @@ fifo_read (void *data, int fd)
     {
         if (num_read < 0)
         {
+#ifdef __CYGWIN__
             if ((errno == EAGAIN) || (errno == ECOMM))
+#else
+            if (errno == EAGAIN)
+#endif /* __CYGWIN__ */
                 return WEECHAT_RC_OK;
 
             weechat_printf (NULL,