rust 2021: TryFrom is now in the prelude

We don't need to explicitly import it anymore. This is the only explicit
import we had that got added to the prelude in Rust 2021.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

src/capi/procfs.rs

@@ -24,10 +24,7 @@ use crate::{
     procfs::{ProcfsBase, GLOBAL_PROCFS_HANDLE},
 };
 
-use std::{
-    convert::TryFrom,
-    os::unix::io::{OwnedFd, RawFd},
-};
+use std::os::unix::io::{OwnedFd, RawFd};
 
 use libc::{c_char, c_int, size_t};
 use open_enum::open_enum;