change: ulwip,dhcp,怀疑udp_sendto_if可能返回异常,加上日志打印

components/network/ulwip/src/ulwip_dhcp_client.c

@@ -107,7 +107,10 @@ on_check:
     }
     data = p->payload;
     LLOGI("dhcp payload len %d %02X%02X%02X%02X", p->tot_len, data[0], data[1], data[2], data[3]);
-    udp_sendto_if(s_ulwip_dhcp, p, IP_ADDR_BROADCAST, 67, netif);
+    result = udp_sendto_if(s_ulwip_dhcp, p, IP_ADDR_BROADCAST, 67, netif);
+    if (result != ERR_OK) {
+        LLOGE("dhcp udp_sendto_if error %d", result);
+    }
     pbuf_free(p);
     return 0;
 }