async: fdio: remove unused member

clang warns about an unused private field ('fd') because it is
a capture-only member.  There isn't any reason to keep the fd
around once the underlying sd_event has been created, so remove
it as a member.

Signed-off-by: Patrick Williams <[email protected]>
Change-Id: I176b2c4b53bbd7e4bb4bc9a9594f5816ee1bda2e

Author: williamspatrick

include/sdbusplus/async/fdio.hpp

@@ -34,7 +34,6 @@ class fdio : private context_ref, details::context_friend
     friend fdio_ns::fdio_completion;
 
   private:
-    int fd;
     event_source_t source;
     std::mutex lock{};
     fdio_ns::fdio_completion* complete{nullptr};

src/async/fdio.cpp

@@ -2,7 +2,7 @@
 
 namespace sdbusplus::async
 {
-fdio::fdio(context& ctx, int fd) : context_ref(ctx), fd(fd)
+fdio::fdio(context& ctx, int fd) : context_ref(ctx)
 {
     static auto eventHandler =
         [](sd_event_source*, int, uint32_t, void* data) noexcept {