fixup to Clippy cleanup: mismatched_lifetime_syntaxes

Author: asomers

src/sys/socket/sockopt.rs

@@ -1955,7 +1955,7 @@ pub struct SetOsString<'a> {
 
 #[cfg(any(target_os = "freebsd", linux_android, target_os = "illumos"))]
 impl<'a> Set<'a, OsString> for SetOsString<'a> {
-    fn new(val: &OsString) -> SetOsString {
+    fn new(val: &OsString) -> SetOsString<'_> {
         SetOsString {
             val: val.as_os_str(),
         }