Fix null check in CompositeExecutor ctor

Fixes: #10575

Error in the `CompositeExecutor` constructor where `primaryTaskExecutor` was being validated twice instead of validating `secondaryTaskExecutor`.

Signed-off-by: Yoobin Yoon <[email protected]>

**Auto-cherry-pick to `6.4.x`**

Author: yybmion

spring-integration-core/src/main/java/org/springframework/integration/util/CompositeExecutor.java

@@ -35,6 +35,7 @@
  * executors.
  *
  * @author Gary Russell
+ * @author Yoobin Yoon
  * @since 3.0.3
  *
  */
@@ -46,7 +47,7 @@ public class CompositeExecutor implements Executor {
 
 	public CompositeExecutor(Executor primaryTaskExecutor, Executor secondaryTaskExecutor) {
 		Assert.notNull(primaryTaskExecutor, "'primaryTaskExecutor' cannot be null");
-		Assert.notNull(primaryTaskExecutor, "'secondaryTaskExecutor' cannot be null");
+		Assert.notNull(secondaryTaskExecutor, "'secondaryTaskExecutor' cannot be null");
 		this.primaryTaskExecutor = primaryTaskExecutor;
 		this.secondaryTaskExecutor = secondaryTaskExecutor;
 	}