clang-tidy: Enable performance-unnecessary-value-param check

This check flags value parameter declarations of expensive to copy
types that are copied for each invocation but it would suffice to
pass them by const reference.

Change-Id: I631deda63fcbb74362313c9596bf7e72933b0d0c
Signed-off-by: Pavithra Barithaya <pavithrabarithaya07@gmail.com>
diff --git a/sync_watch.cpp b/sync_watch.cpp
index fdeace6..225bf18 100644
--- a/sync_watch.cpp
+++ b/sync_watch.cpp
@@ -37,7 +37,7 @@
 SyncWatch::SyncWatch(sd_event& loop,
                      std::function<int(int, fs::path&)> syncCallback) :
     inotifyFd(-1),
-    syncCallback(syncCallback), loop(loop)
+    syncCallback(std::move(syncCallback)), loop(loop)
 {
     auto fd = inotify_init1(IN_NONBLOCK);
     if (-1 == fd)