fix: Remove let bindings that are immediately returned

As now caught by clippy. https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return

iox_query/src/exec/non_null_checker.rs

@@ -464,8 +464,6 @@ mod tests {
             value.into(),
         ));
 
-        let output = test_collect(exec as Arc<dyn ExecutionPlan>).await;
+        test_collect(exec as Arc<dyn ExecutionPlan>).await
-
-        output
     }
 }

iox_query/src/exec/split.rs

@@ -432,7 +432,7 @@ fn compute_batch(
             let indices = indices.as_any().downcast_ref::<BooleanArray>().unwrap();
 
             // include null for last batch
-            let batch = if last_batch && indices.null_count() > 0 {
+            if last_batch && indices.null_count() > 0 {
                 // since !Null --> Null, but we want all the
                 // remaining rows, that are not in true_indicies,
                 // transform any nulls into true for this one
@@ -441,8 +441,7 @@ fn compute_batch(
                 filter_record_batch(input_batch, &BooleanArray::from(mapped_indicies))
             } else {
                 filter_record_batch(input_batch, indices)
-            }?;
+            }?
-            batch
         }
         ColumnarValue::Scalar(ScalarValue::Boolean(val)) => {
             let empty_record_batch = RecordBatch::new_empty(input_batch.schema());

query_tests/src/scenarios/delete.rs

@@ -241,7 +241,7 @@ impl DbSetup for ThreeDeleteThreeChunks {
         // Scenarios
         // All threee deletes will be applied to every chunk but due to their predicates,
         // only appropriate data is deleted
-        let scenarios = make_n_chunks_scenario(&[
+        make_n_chunks_scenario(&[
             ChunkData {
                 lp_lines: lp_lines_1,
                 preds: preds.clone(),
@@ -264,8 +264,6 @@ impl DbSetup for ThreeDeleteThreeChunks {
                 ..Default::default()
             },
         ])
-        .await;
+        .await
-
-        scenarios
     }
 }

query_tests/src/scenarios/library.rs

@@ -506,9 +506,7 @@ impl DbSetup for ManyFieldsSeveralChunks {
             ..Default::default()
         };
 
-        let scenarios = make_n_chunks_scenario(&[c1, c2, c3, c4, c5]).await;
+        make_n_chunks_scenario(&[c1, c2, c3, c4, c5]).await
-
-        scenarios
     }
 }
 
@@ -591,7 +589,7 @@ impl DbSetup for OneMeasurementFourChunksWithDuplicates {
             "h2o,state=CA,city=SJ min_temp=75.5,max_temp=84.08 700",
         ];
 
-        let scenarios = make_n_chunks_scenario(&[
+        make_n_chunks_scenario(&[
             ChunkData {
                 lp_lines: lp_lines1,
                 partition_key,
@@ -613,9 +611,7 @@ impl DbSetup for OneMeasurementFourChunksWithDuplicates {
                 ..Default::default()
             },
         ])
-        .await;
+        .await
-
-        scenarios
     }
 }