tracing/syscalls: Add fields format for exit events

Add "format" file for syscall exit events:

 # cat events/syscalls/sys_exit_open/format
 name: sys_exit_open
 ID: 344
 format:
         field:unsigned short common_type;       offset:0;       size:2;
         field:unsigned char common_flags;       offset:2;       size:1;
         field:unsigned char common_preempt_count;       offset:3;       size:1;
         field:int common_pid;   offset:4;       size:4;
         field:int common_tgid;  offset:8;       size:4;

         field:int nr;   offset:12;      size:4;
         field:unsigned long ret;        offset:16;      size:4;

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAF61.3060307@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/trace/syscall.h b/include/trace/syscall.h
index 0cb0362..5ce85d7 100644
--- a/include/trace/syscall.h
+++ b/include/trace/syscall.h
@@ -55,8 +55,10 @@
 extern void unreg_event_syscall_enter(void *ptr);
 extern int reg_event_syscall_exit(void *ptr);
 extern void unreg_event_syscall_exit(void *ptr);
-extern int
-ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s);
+extern int syscall_enter_format(struct ftrace_event_call *call,
+				struct trace_seq *s);
+extern int syscall_exit_format(struct ftrace_event_call *call,
+				struct trace_seq *s);
 enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags);
 enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags);
 #endif