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, 9 insertions, 14 deletions

diff --git a/src/libstd/sys/unix/memchr.rs b/src/libstd/sys/unix/memchr.rs
index 1984678bdde..a9273ea676c 100644
--- a/src/libstd/sys/unix/memchr.rs
+++ b/src/libstd/sys/unix/memchr.rs
@@ -6,32 +6,27 @@ pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
         libc::memchr(
             haystack.as_ptr() as *const libc::c_void,
             needle as libc::c_int,
-            haystack.len())
+            haystack.len(),
+        )
     };
-    if p.is_null() {
-        None
-    } else {
-        Some(p as usize - (haystack.as_ptr() as usize))
-    }
+    if p.is_null() { None } else { Some(p as usize - (haystack.as_ptr() as usize)) }
 }
 
 pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> {
-
     #[cfg(target_os = "linux")]
     fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
         // GNU's memrchr() will - unlike memchr() - error if haystack is empty.
-        if haystack.is_empty() {return None}
+        if haystack.is_empty() {
+            return None;
+        }
         let p = unsafe {
             libc::memrchr(
                 haystack.as_ptr() as *const libc::c_void,
                 needle as libc::c_int,
-                haystack.len())
+                haystack.len(),
+            )
         };
-        if p.is_null() {
-            None
-        } else {
-            Some(p as usize - (haystack.as_ptr() as usize))
-        }
+        if p.is_null() { None } else { Some(p as usize - (haystack.as_ptr() as usize)) }
     }
 
     #[cfg(not(target_os = "linux"))]