[MINOR] clean up style for storage param setters in ALS

Clean up style for param setter methods in ALS to match standard style and the other setter in class (this is an artefact of one of my previous PRs that wasn't cleaned up).

## How was this patch tested?
Existing tests - no functionality change.

Author: Nick Pentreath <[email protected]>

Closes #13480 from MLnick/als-param-minor-cleanup.

(cherry picked from commit ccd298e)
Signed-off-by: Nick Pentreath <[email protected]>

Author: Nick Pentreath

mllib/src/main/scala/org/apache/spark/ml/recommendation/ALS.scala

@@ -430,15 +430,11 @@ class ALS(@Since("1.4.0") override val uid: String) extends Estimator[ALSModel]
 
   /** @group expertSetParam */
   @Since("2.0.0")
-  def setIntermediateStorageLevel(value: String): this.type = {
-    set(intermediateStorageLevel, value)
-  }
+  def setIntermediateStorageLevel(value: String): this.type = set(intermediateStorageLevel, value)
 
   /** @group expertSetParam */
   @Since("2.0.0")
-  def setFinalStorageLevel(value: String): this.type = {
-    set(finalStorageLevel, value)
-  }
+  def setFinalStorageLevel(value: String): this.type = set(finalStorageLevel, value)
 
   /**
    * Sets both numUserBlocks and numItemBlocks to the specific value.