I propose exposing the std::os::fd::AsRawFd trait method for nix::sys::fanotify::Fanotify struct (nix-rust#2575)

* Exposed the ```std::os::fd::AsRawFd``` trait method for ```nix::sys::fanotify::Fanotify``` struct

* Pull request number is set

Author: ChrysoliteAzalea

changelog/2575.added.md

@@ -0,0 +1 @@
+Exposed the ```std::os::fd::AsRawFd``` trait method for ```nix::sys::fanotify::Fanotify``` struct

src/sys/fanotify.rs

@@ -419,6 +419,13 @@ impl AsFd for Fanotify {
     }
 }
 
+impl AsRawFd for Fanotify {
+    fn as_raw_fd(&self) -> RawFd
+    {
+        self.fd.as_raw_fd()
+    }
+}
+
 impl From<Fanotify> for OwnedFd {
     fn from(value: Fanotify) -> Self {
         value.fd