Respond to review comments

README.md

@@ -105,7 +105,7 @@ The following targets are supported by `nix`:
 
 ## Minimum Supported Rust Version (MSRV)
 
-nix is supported on Rust 1.65 and higher.  Its MSRV will not be
+nix is supported on Rust 1.69 and higher.  Its MSRV will not be
 changed in the future without bumping the major or minor version.
 
 ## Contributing

src/mount/bsd.rs

@@ -396,7 +396,11 @@ impl<'a> Nmount<'a> {
         match Errno::result(res) {
             Ok(_) => Ok(()),
             Err(error) => {
-                let errmsg = CStr::from_bytes_until_nul(&errmsg[..]).ok();
+                let errmsg = if errmsg[0] == 0 {
+                    None
+                } else {
+                    CStr::from_bytes_until_nul(&errmsg[..]).ok()
+                };
                 Err(NmountError::new(error, errmsg))
             }
         }

src/sys/prctl.rs

@@ -151,11 +151,11 @@ pub fn get_name() -> Result<CString> {
 
     let res = unsafe { libc::prctl(libc::PR_GET_NAME, &buf, 0, 0, 0) };
 
-    Errno::result(res).map(|_| {
+    Errno::result(res).and_then(|_| {
         CStr::from_bytes_until_nul(&buf)
             .map(CStr::to_owned)
             .map_err(|_| Errno::EINVAL)
-    }).flatten()
+    })
 }
 
 /// Sets the timer slack value for the calling thread. Timer slack is used by the kernel to group