elevator: update the document of elevator_match

elevator_match does not care about elevator_features any more. Remove
related descriptions from its document.

Fixes: ffb86425 ("block: don't check for required features in elevator_match")
Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/a58424555202c07a9ccf7f60c3ad7e247da09e25.1669126766.git.nickyc975@zju.edu.cnSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/elevator.c

@@ -91,12 +91,11 @@ static inline bool elv_support_features(struct request_queue *q,
 }
 
 /**
- * elevator_match - Test an elevator name and features
+ * elevator_match - Check whether @e's name or alias matches @name
  * @e: Scheduler to test
  * @name: Elevator name to test
  *
- * Return true if the elevator @e name matches @name and if @e provides all
- * the features specified by @required_features.
+ * Return true if the elevator @e's name or alias matches @name.
  */
 static bool elevator_match(const struct elevator_type *e, const char *name)
 {