spring-projectsGH-8699: Atomic Redis script for unlock()

Add a comment and fix checkstyle violations

Author: EddieChoCho

spring-integration-redis/src/main/java/org/springframework/integration/redis/util/RedisLockRegistry.java

@@ -478,6 +478,7 @@ private void removeLockKey() {
 			if (RedisLockRegistry.this.unlinkAvailable) {
 				Boolean unlinkResult = null;
 				try {
+					// Attempt to UNLINK the lock key; an exception indicates lack of UNLINK support
 					unlinkResult = removeLockKeyInnerUnlink();
 				}
 				catch (Exception ex) {
@@ -492,7 +493,8 @@ private void removeLockKey() {
 					}
 				}
 
-				if(Boolean.TRUE.equals(unlinkResult)) {
+				if (Boolean.TRUE.equals(unlinkResult)) {
+					// Lock key successfully unlinked
 					return;
 				}
 				else if (Boolean.FALSE.equals(unlinkResult)) {