Fix FreeBSD's get_os uname's pattern matching

The previous code would lead to compilation error on the latest
FreeBSD (14.0) release. Both with the rust pkg (version 1.72), as well
as with the latest stable compiler (version 1.76).

Compilation error was about mismatched types, with the pattern match
branches being Option<&str>, when a &str was currently expected.
Compiler's advised fix was to wrap the branch patterns in a `Some`,
which was done in this commit.

os_info/src/freebsd/mod.rs

@@ -25,8 +25,8 @@ pub fn current_platform() -> Info {
 
 fn get_os() -> Type {
     match uname("-r").as_deref() {
-        "MidnightBSD" => Type::MidnightBSD,
-        "FreeBSD" => {
+        Some("MidnightBSD") => Type::MidnightBSD,
+        Some("FreeBSD") => {
             let check_hardening = match Command::new("/sbin/sysctl")
                 .arg("hardening.version")
                 .output()