fixup to 4f6f119: skip test_acct if jailed

Rust 1.24.1 is more picky about use paths

Author: asomers

test/test.rs

@@ -32,9 +32,9 @@ macro_rules! require_capability {
 #[cfg(target_os = "freebsd")]
 macro_rules! skip_if_jailed {
     ($name:expr) => {
-        use sysctl::CtlValue;
+        use ::sysctl::CtlValue;
 
-        if let CtlValue::Int(1) = sysctl::value("security.jail.jailed")
+        if let CtlValue::Int(1) = ::sysctl::value("security.jail.jailed")
             .unwrap()
         {
             use ::std::io::Write;