selftests/timens: add futex binary to .gitignore

Add the futex test binary introduced by commit a4fd841
("selftests/timens: Add a test for futex()") to .gitignore.

Signed-off-by: Tobias Klauser <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

Author: tklauser

tools/testing/selftests/timens/.gitignore

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 clock_nanosleep
 exec
+futex
 gettime_perf
 gettime_perf_cold
 procfs