tracing: Fix trace_pid_list_free() kernel-doc

make C=1 reports:

kernel/trace/pid_list.c:458: warning: Function parameter or struct member 'pid_list' not described in 'trace_pid_list_free'

Add the missing parameter to the trace_pid_list_free() kernel-doc.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Signed-off-by: Jeff Johnson <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: Jeff Johnson

kernel/trace/pid_list.c

@@ -451,6 +451,7 @@ struct trace_pid_list *trace_pid_list_alloc(void)
 
 /**
  * trace_pid_list_free - Frees an allocated pid_list.
+ * @pid_list: The pid list to free.
  *
  * Frees the memory for a pid_list that was allocated.
  */