tests: fix errors/warnings for uptime on OpenBSD

Signed-off-by: Laurent Cheylus <foxy@free.fr>

Author: lcheylus

tests/by-util/test_uptime.rs

@@ -6,10 +6,12 @@
 // spell-checker:ignore bincode serde utmp runlevel testusr testx
 #![allow(clippy::cast_possible_wrap, clippy::unreadable_literal)]
 
-#[cfg(not(target_os = "openbsd"))]
 use uutests::at_and_ucmd;
+use uutests::new_ucmd;
+#[cfg(not(target_os = "openbsd"))]
 use uutests::util::TestScenario;
-use uutests::{new_ucmd, util_name};
+#[cfg(not(target_os = "openbsd"))]
+use uutests::util_name;
 
 use regex::Regex;