block: remove useless BUG_ON() in blk_mq_put_tag()

Since the if condition in blk_mq_put_tag() checks that the tag to put is
not a reserved one, the BUG_ON() check in the else branch checking if
the tag is indeed a reserved one is useless. Remove it.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220602075159.1273366-1-damien.lemoal@opensource.wdc.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>