Comment unused parameters

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Id5448711b5a6910514264ff9c008b7d32c26a8f8
diff --git a/occ_errors.cpp b/occ_errors.cpp
index a356378..c6f450d 100644
--- a/occ_errors.cpp
+++ b/occ_errors.cpp
@@ -100,8 +100,8 @@
 }
 
 // Callback handler when there is an activity on the FD
-int Error::processEvents(sd_event_source* es, int fd, uint32_t revents,
-                         void* userData)
+int Error::processEvents(sd_event_source* /*es*/, int /*fd*/,
+                         uint32_t /*revents*/, void* userData)
 {
     auto error = static_cast<Error*>(userData);