build: silent cllipy complaints.

cargo clippy --features=fusedev --target-dir target-fusedev --
-Dclippy::all
    Checking fuse-rs v0.1.0 (/root/git_repo/fuse-backend-rs)
error: using `Option.and_then(|x| Some(y))`, which is more succinctly
expressed as `map(|x| y)`
   -->
/root/git_repo/fuse-backend-rs/src/transport/fusedev/mod.rs:166:17
    |
166 | /                 e.as_errno()
167 | |                     .and_then(|r|
Some(io::Error::from_raw_os_error(r as i32)))
    |
|_______________________________________________________________________________^
help: try this: `e.as_errno().map(|r| io::Error::from_raw_os_error(r as
i32))`
    |
    = note: `-D clippy::bind-instead-of-map` implied by `-D clippy::all`
    = help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#bind_instead_of_map

Signed-off-by: Changwei Ge <chge@linux.alibaba.com>

Author: Changwei Ge

src/transport/fusedev/mod.rs

@@ -164,7 +164,7 @@ impl<'a> Writer<'a> {
             return writev(self.fd, buf.as_slice()).map_err(|e| {
                 error! {"fail to write to fuse device on commit: {}", e};
                 e.as_errno()
-                    .and_then(|r| Some(io::Error::from_raw_os_error(r as i32)))
+                    .map(|r| io::Error::from_raw_os_error(r as i32))
                     .unwrap_or_else(|| io::Error::new(io::ErrorKind::Other, format!("{}", e)))
             });
         }