Format libstd/sys with rustfmt

This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd/sys *that are not involved in any currently open PR*
to minimize merge conflicts. THe list of files involved in open PRs was
determined by querying GitHub's GraphQL API with this script:
https://gist.github.com/dtolnay/aa9c34993dc051a4f344d1b10e4487e8

With the list of files from the script in outstanding_files, the
relevant commands were:

    $ find src/libstd/sys -name '*.rs' \
        | xargs rustfmt --edition=2018 --unstable-features --skip-children
    $ rg libstd/sys outstanding_files | xargs git checkout --

Repeating this process several months apart should get us coverage of
most of the rest of the files.

To confirm no funny business:

    $ git checkout $THIS_COMMIT^
    $ git show --pretty= --name-only $THIS_COMMIT \
        | xargs rustfmt --edition=2018 --unstable-features --skip-children
    $ git diff $THIS_COMMIT  # there should be no difference

1 files changed, 5 insertions, 4 deletions

diff --git a/src/libstd/sys/windows/path.rs b/src/libstd/sys/windows/path.rs
index 7eae28cb14f..524f21f889b 100644
--- a/src/libstd/sys/windows/path.rs
+++ b/src/libstd/sys/windows/path.rs
@@ -1,6 +1,6 @@
-use crate::path::Prefix;
 use crate::ffi::OsStr;
 use crate::mem;
+use crate::path::Prefix;
 
 fn os_str_as_u8_slice(s: &OsStr) -> &[u8] {
     unsafe { mem::transmute(s) }
@@ -38,8 +38,9 @@ pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
                     // \\?\UNC\server\share
                     path = &path[4..];
                     let (server, share) = match parse_two_comps(path, is_verbatim_sep) {
-                        Some((server, share)) =>
-                            (u8_slice_as_os_str(server), u8_slice_as_os_str(share)),
+                        Some((server, share)) => {
+                            (u8_slice_as_os_str(server), u8_slice_as_os_str(share))
+                        }
                         None => (u8_slice_as_os_str(path), u8_slice_as_os_str(&[])),
                     };
                     return Some(VerbatimUNC(server, share));
@@ -70,7 +71,7 @@ pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
                 }
                 _ => (),
             }
-        } else if path.get(1) == Some(& b':') {
+        } else if path.get(1) == Some(&b':') {
             // C:
             let c = path[0];
             if c.is_ascii() && (c as char).is_alphabetic() {