UVI-2021-1001291 coresight: tmc-etf: Fix global-out-of-bounds in tmc_update_etf_buffer()

Fix global-out-of-bounds in tmc_update_etf_buffer(). This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.10.51 by commit 35c1c4bd2d59ad734129d4e232af9d1098023918, it was introduced in version v4.14 by commit 0c3fc4d5fa26092853278145aca9b21fa52a3e93. For more details please see the references link