libtracefs/Documentation: Fix function-filter call to tracefs_list_free()

The function-filter man page example used tracefs_free_list() instead of
tracefs_list_free()

Link: https://lore.kernel.org/linux-trace-devel/20211122234956.788401-9-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
1 file changed