use correct type for tv_usec

src/time.rs

@@ -20,7 +20,7 @@ impl timeval {
 	pub fn from_usec(microseconds: u64) -> Self {
 		Self {
 			tv_sec: (microseconds / 1_000_000) as i64,
-			tv_usec: (microseconds % 1_000_000) as i32,
+			tv_usec: (microseconds % 1_000_000) as u32,
 		}
 	}