buffer: remove useless comment and WB_REASON_FREE_MORE_MEM, reason.
free_more_memory func has been completely removed in commit
bc48f001de12
("buffer: eliminate the need to call free_more_memory() in __getblk_slow()")
So comment and `WB_REASON_FREE_MORE_MEM` reason about free_more_memory
are no longer needed.
Fixes: bc48f001de12 ("buffer: eliminate the need to call free_more_memory() in __getblk_slow()")
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Zhiqiang Liu <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>