block: Catch possible entries missing from hctx_flag_name[]

Refresh values in BLK_MQ_F_x enum, and then re-arrange members in
hctx_flag_name[] to match that enum. Renumber
BLK_MQ_F_ALLOC_POLICY_START_BIT to match the value refresh.

Add a BUILD_BUG_ON() call to ensure that we are not missing entries in
hctx_flag_name[].

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-11-john.g.garry@oracle.com


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