tracing: Use init_utsname()->release

Instead of using UTS_RELEASE, use init_utsname()->release, which means that
we don't need to rebuild the code just for the git head commit changing.

Link: https://lore.kernel.org/linux-trace-kernel/20240222124639.65629-1-john.g.garry@oracle.com



Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>