Revert "block, bfq: honor already-setup queue merges"

Revert "block, bfq: honor already-setup queue merges"

This reverts commit fde25220c9a54ad2df67bae8072231c2e122f4ef.

We have had several folks complain that this causes hangs for them, which
is especially problematic as the commit has also hit stable already.

As no resolution seems to be forthcoming right now, revert the patch.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=214503
Fixes: fde25220c9a5 ("block, bfq: honor already-setup queue merges")
Signed-off-by: Jens Axboe <axboe@kernel.dk>