sunrpc: fix duplicated word in <linux/sunrpc/cache.h>

Change "time time" to "time expiry_time" to match the field name.

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: "J. Bruce Fields" <[e-mail]>
Cc: Chuck Lever <[e-mail]>
Cc: Trond Myklebust <[e-mail]>
Cc: Anna Schumaker <[e-mail]>
Cc: [e-mail]
Signed-off-by: Anna Schumaker <[e-mail]>

include/linux/sunrpc/cache.h

···
  */
 struct cache_head {
 	struct hlist_node	cache_list;
-	time64_t	expiry_time;	/* After time time, don't use the data */
+	time64_t	expiry_time;	/* After time expiry_time, don't use
+					 * the data */
 	time64_t	last_refresh;   /* If CACHE_PENDING, this is when upcall was
 					 * sent, else this is when update was
 					 * received, though it is alway set to