irq: Fix typo in tracepoint.xml

This patch fix a spelling typo found in DocBook/tracepoint.xml.
It is because the file was created from comments in source,
so I have to fix the typo in include/trace/events/irq.h

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

include/trace/events/irq.h

@@ -75,7 +75,7 @@ TRACE_EVENT(irq_handler_entry,
  * @ret: return value
  *
  * If the @ret value is set to IRQ_HANDLED, then we know that the corresponding
- * @action->handler scuccessully handled this irq. Otherwise, the irq might be
+ * @action->handler successfully handled this irq. Otherwise, the irq might be
  * a shared irq line, or the irq was not handled successfully. Can be used in
  * conjunction with the irq_handler_entry to understand irq handler latencies.
  */