Revert "net: tcp: Add DEBUGASSERT() in psock_tcp_send()"

Summary:
- Based on the discussion (PR#2772), let me revert the commit

Impact:
- None

Testing:
- N/A

This reverts commit ec8bf5c8c1.

Suggested-by: YAMAMOTO Takashi <yamamoto@midokura.com>
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

net/tcp/tcp_send_buffered.c

@@ -1143,11 +1143,6 @@ ssize_t psock_tcp_send(FAR struct socket *psock, FAR const void *buf,
            */
 
           blresult = net_breaklock(&count);
-
-          /* NOTE: At least IOB needs to hold the packet */
-
-          DEBUGASSERT((CONFIG_IOB_NBUFFERS * CONFIG_IOB_BUFSIZE) > len);
-
           result = TCP_WBCOPYIN(wrb, (FAR uint8_t *)buf, len);
           if (blresult >= 0)
             {