metrics: tests: replace .get(N).unwrap() with array indexing

This is more concise and accomplishes the same thing. It also
incidentally avoids a clippy warning about using .get(0) instead of
.first().

BUG=b:344974550
TEST=tools/clippy

Change-Id: Ie8575f63ca7aacd91123c81a6f533b4a2d1408d2
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/5598299
Commit-Queue: Daniel Verkamp <[email protected]>
Reviewed-by: Noah Gold <[email protected]>

metrics/src/local_stats.rs

@@ -571,9 +571,9 @@ mod tests {
             simple_stats.add(v);
         }
 
-        bucket_check(histogram.buckets.get(0).unwrap(), &[0, 9, 5]);
-        bucket_check(histogram.buckets.get(1).unwrap(), &[20, 50]);
-        bucket_check(histogram.buckets.get(2).unwrap(), &[199, 120]);
+        bucket_check(&histogram.buckets[0], &[0, 9, 5]);
+        bucket_check(&histogram.buckets[1], &[20, 50]);
+        bucket_check(&histogram.buckets[2], &[199, 120]);
         assert_eq!(histogram.buckets.len(), 3);
         assert_eq!(histogram.simple_stat(), simple_stats);
         assert_eq!(histogram.values, None);
@@ -592,9 +592,9 @@ mod tests {
             simple_stats.add(v);
         }
 
-        bucket_check(histogram.buckets.get(1).unwrap(), &[4, 9, 5]);
-        bucket_check(histogram.buckets.get(2).unwrap(), &[20, 50]);
-        bucket_check(histogram.buckets.get(3).unwrap(), &[199, 120]);
+        bucket_check(&histogram.buckets[1], &[4, 9, 5]);
+        bucket_check(&histogram.buckets[2], &[20, 50]);
+        bucket_check(&histogram.buckets[3], &[199, 120]);
         assert_eq!(histogram.buckets.len(), 5);
         assert_eq!(histogram.simple_stat(), simple_stats);
         assert_eq!(histogram.values, None);
@@ -637,9 +637,9 @@ mod tests {
             histogram.add(v.clone()).unwrap();
         }
 
-        bucket_check(histogram.buckets.get(0).unwrap(), &[4, 9, 5]);
-        bucket_check(histogram.buckets.get(1).unwrap(), &[20, 50]);
-        bucket_check(histogram.buckets.get(2).unwrap(), &[199, 120]);
+        bucket_check(histogram.buckets[0], &[4, 9, 5]);
+        bucket_check(histogram.buckets[1], &[20, 50]);
+        bucket_check(histogram.buckets[2], &[199, 120]);
         assert_eq!(histogram.buckets.len(), 3);
         assert_eq!(histogram.simple_stat(), simple_stats);
         assert_eq!(histogram.values, Some(values));
@@ -661,11 +661,11 @@ mod tests {
             histogram.add(v.clone()).unwrap();
         }
 
-        bucket_check(histogram.buckets.get(0).unwrap(), &[]);
-        bucket_check(histogram.buckets.get(4).unwrap(), &[]);
-        bucket_check(histogram.buckets.get(1).unwrap(), &[4, 9, 5]);
-        bucket_check(histogram.buckets.get(2).unwrap(), &[20, 50]);
-        bucket_check(histogram.buckets.get(3).unwrap(), &[199, 120]);
+        bucket_check(histogram.buckets[0], &[]);
+        bucket_check(histogram.buckets[4], &[]);
+        bucket_check(histogram.buckets[1], &[4, 9, 5]);
+        bucket_check(histogram.buckets[2], &[20, 50]);
+        bucket_check(histogram.buckets[3], &[199, 120]);
         assert_eq!(histogram.buckets.len(), 5);
         assert_eq!(histogram.simple_stat(), simple_stats);
         assert_eq!(histogram.values, Some(values));