perf tools: Remove libtraceevent in .gitignore

The libtraceevent has been removed from the source tree, and .gitignore
needs to be updated as well.

Fixes: 4171925 ("tools lib traceevent: Remove libtraceevent")
Signed-off-by: Chen Pei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

Author: cp0613

tools/perf/.gitignore

@@ -48,8 +48,6 @@ libbpf/
 libperf/
 libsubcmd/
 libsymbol/
-libtraceevent/
-libtraceevent_plugins/
 fixdep
 Documentation/doc.dep
 python_ext_build/