tracing: Add comment to describe special break case in probe_remove_event_call()

The "break" used in the do_for_each_event_file() is used as an optimization
as the loop is really a double loop. The loop searches all event files
for each trace_array. There's only one matching event file per trace_array
and after we find the event file for the trace_array, the break is used
to jump to the next trace_array and start the search there.

As this is not a standard way of using "break" in C code, it requires
a comment right before the break to let people know what is going on.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace_events.c

@@ -1732,6 +1732,12 @@ static int probe_remove_event_call(struct ftrace_event_call *call)
 		 */
 		if (file->flags & FTRACE_EVENT_FL_ENABLED)
 			return -EBUSY;
+		/*
+		 * The do_for_each_event_file_safe() is
+		 * a double loop. After finding the call for this
+		 * trace_array, we use break to jump to the next
+		 * trace_array.
+		 */
 		break;
 	} while_for_each_event_file();