selftests/ftrace: Fix eprobe syntax test case to check filter support

selftests/ftrace: Fix eprobe syntax test case to check filter support

commit a457e944df92789ab31aaf35fae9db064e3c51c4 upstream.

Fix eprobe syntax test case to check whether the kernel supports the filter
on eprobe for filter syntax test command. Without this fix, this test case
will fail if the kernel supports eprobe but doesn't support the filter on
eprobe.

Link: https://lore.kernel.org/all/167309834742.640500.379128668288448035.stgit@devnote3/
Fixes: 9e14bae7d049 ("selftests/ftrace: Add eprobe syntax error testcase")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>