fix unused parameter warnings

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic045f61b3657f1a21afd82b9975619a8fb440863
diff --git a/watch.cpp b/watch.cpp
index ef93584..cfca68e 100644
--- a/watch.cpp
+++ b/watch.cpp
@@ -68,8 +68,7 @@
     }
 
     ioPtr = std::make_unique<sdeventplus::source::IO>(
-        event, fd, EPOLLIN,
-        [this](sdeventplus::source::IO&, int fd, uint32_t revents) {
+        event, fd, EPOLLIN, [this](sdeventplus::source::IO&, int fd, uint32_t) {
             const int size = sizeof(struct inotify_event) + NAME_MAX + 1;
             std::array<char, size> buffer;
             int length = read(fd, buffer.data(), buffer.size());