mm/slab_common.c: delete duplicated word

Drop the repeated word "and".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200801173822.14973-12-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slab_common.c

@@ -419,7 +419,7 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
 	/*
 	 * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
 	 * @slab_caches_to_rcu_destroy list.  The slab pages are freed
-	 * through RCU and and the associated kmem_cache are dereferenced
+	 * through RCU and the associated kmem_cache are dereferenced
 	 * while freeing the pages, so the kmem_caches should be freed only
 	 * after the pending RCU operations are finished.  As rcu_barrier()
 	 * is a pretty slow operation, we batch all pending destructions