wireless: gs2200m: Fix error handling in sendto_request()

Summary:
- This commit returns -errno to the caller

Impact:
- gs2200m only

Testing:
- Tested with spresense:wifi_smp
- NOTE: need to update the gs2200m driver in NuttX

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

wireless/gs2200m/gs2200m_main.c

@@ -815,7 +815,7 @@ static int sendto_request(int fd, FAR struct gs2200m_s *priv,
 
       if (0 != nret)
         {
-          ret = -EINVAL;
+          ret = -errno;
           goto prepare;
         }