Remove unneeded std::time::Instant imports

crates/common/src/lib.rs

@@ -1,12 +1,10 @@
-use std::time::Instant;
-
 #[macro_export]
 macro_rules! instrument {
     ($part1:expr, $part2:expr) => {
-        let mut now = Instant::now();
+        let mut now = std::time::Instant::now();
         println!("Part 1: {}", $part1);
         println!("(elapsed: {:?})", now.elapsed());
-        now = Instant::now();
+        now = std::time::Instant::now();
         println!("");
         println!("Part 2: {}", $part2);
         println!("(elapsed: {:?})", now.elapsed());