netd - pass file descriptors as 'const unique_fd&'s not raw ints.

Test: builds, atest
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I5947f70647f81d20d00af913df7ec4c5fd971b4c
diff --git a/server/TrafficController.cpp b/server/TrafficController.cpp
index 0de2370..4e3a3f4 100644
--- a/server/TrafficController.cpp
+++ b/server/TrafficController.cpp
@@ -247,7 +247,7 @@
     return netdutils::status::ok;
 }
 
-static Status attachProgramToCgroup(const char* programPath, const int cgroupFd,
+static Status attachProgramToCgroup(const char* programPath, const unique_fd& cgroupFd,
                                     bpf_attach_type type) {
     unique_fd cgroupProg(bpfFdGet(programPath, 0));
     if (cgroupProg == -1) {