Merge pull request scala#6645 from xuwei-k/patch-1

fix Set#-- deprecated message

Author: julienrf

src/library/scala/collection/Set.scala

@@ -152,7 +152,7 @@ trait SetOps[A, +CC[_], +C <: SetOps[A, CC, C]]
   /** Alias for `diff` */
   @`inline` final def &~ (that: Set[A]): C = this diff that
 
-  @deprecated("Use &- or diff instead of --", "2.13.0")
+  @deprecated("Use &~ or diff instead of --", "2.13.0")
   @`inline` final def -- (that: Set[A]): C = diff(that)
 
   /** Creates a new $coll by adding all elements contained in another collection to this $coll, omitting duplicates.