tracing: Convert some signal events to DEFINE_TRACE

Use DECLARE_EVENT_CLASS to remove duplicate code:

text    data     bss     dec     hex filename
  23639    6084       8   29731    7423 kernel/signal.o.orig
  22727    6084       8   28819    7093 kernel/signal.o

2 events are converted:

  signal_queue_overflow: signal_overflow_fail, signal_lose_info

No functional change.

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BA97FBD.8070703@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>