tools/gpio: fix gpio-event-mon header comment

Fixes: 97f69747d8b1 ('tools/gpio: add the gpio-event-mon tool')
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c
index 448ed96..1c14c25 100644
--- a/tools/gpio/gpio-event-mon.c
+++ b/tools/gpio/gpio-event-mon.c
@@ -1,5 +1,5 @@
 /*
- * gpio-hammer - example swiss army knife to shake GPIO lines on a system
+ * gpio-event-mon - monitor GPIO line events from userspace
  *
  * Copyright (C) 2016 Linus Walleij
  *