[SPARK-44880][UI] Remove unnecessary right curly brace at the end of …

…the thread locks info

### What changes were proposed in this pull request?

Remove unnecessary curly braces at the end of the thread locks info.

### Why are the changes needed?

<img width="1405" alt="image" src="https://github.com/apache/spark/assets/8326978/34bb71e9-1982-4856-bb55-e10cd6fcf707">

the right curly brace is dangling.

### Does this PR introduce _any_ user-facing change?

no

### How was this patch tested?

existing ut

### Was this patch authored or co-authored using generative AI tooling?

no

Closes #42571 from yaooqinn/SPARK-44880.

Authored-by: Kent Yao <yao@apache.org>
Signed-off-by: Yuming Wang <yumwang@ebay.com>

core/src/main/scala/org/apache/spark/util/Utils.scala

@@ -2109,9 +2109,9 @@ private[spark] object Utils
     def lockString: String = {
       lock match {
         case monitor: MonitorInfo =>
-          s"Monitor(${lock.getClassName}@${lock.getIdentityHashCode}})"
+          s"Monitor(${lock.getClassName}@${monitor.getIdentityHashCode})"
         case _ =>
-          s"Lock(${lock.getClassName}@${lock.getIdentityHashCode}})"
+          s"Lock(${lock.getClassName}@${lock.getIdentityHashCode})"
       }
     }
   }