net: fix skb leak in __skb_tstamp_tx()

In the Linux kernel, the following vulnerability has been resolved:

net: fix skb leak in __skb_tstamp_tx()

Commit 50749f2dd685 ("tcp/udp: Fix memleaks of sk and zerocopy skbs with

TX timestamp.") added a call to skb_orphan_frags_rx() to fix leaks with

zerocopy skbs. But it ended up adding a leak of its own. When

skb_orphan_frags_rx() fails, the function just returns, leaking the skb

it just cloned. Free it before returning.

This bug was discovered and resolved using Coverity Static Analysis

Security Testing (SAST) by Synopsys, Inc.