hashtable: remove repeated phrase from a comment

"in a rcu enabled hashtable" is repeated twice in a comment.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/hashtable.h

@@ -167,7 +167,6 @@ static inline void hash_del_rcu(struct hlist_node *node)
 /**
  * hash_for_each_possible_rcu - iterate over all possible objects hashing to the
  * same bucket in an rcu enabled hashtable
- * in a rcu enabled hashtable
  * @name: hashtable to iterate
  * @obj: the type * to use as a loop cursor for each entry
  * @member: the name of the hlist_node within the struct