FreeBSD: solve lint issues

Signed-off-by: Lokesh Mandvekar <[email protected]>

Author: lsm5

cmd/podman/system/service_abi_common.go

@@ -2,9 +2,5 @@
 
 package system
 
-// Currently, we only need servicereaper on Linux to support slirp4netns.
-func maybeStartServiceReaper() {
-}
-
 // There is no cgroup on non linux.
 func maybeMoveToSubCgroup() {}

libpod/container.go

@@ -107,7 +107,9 @@ type Container struct {
 	runtime    *Runtime
 	ociRuntime OCIRuntime
 
+	// nolint:unused // Used on Linux for rootless port mapping via RLK
 	rootlessPortSyncR *os.File
+	// nolint:unused // Used on Linux for rootless port mapping via RLK
 	rootlessPortSyncW *os.File
 
 	// reservedPorts contains the fds for the bound ports when using the