blktrace: don't centralize grabbing q->debugfs_mutex in blk_trace_ioctl

Call each handler directly and the handler do grab q->debugfs_mutex,
prepare for killing dependency between ->debug_mutex and ->mmap_lock.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241128125029.4152292-2-ming.lei@redhat.com


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