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

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

This reverts commit 25e159ba6dbebbcc2f2d4c2b88c7ff0616ca9ae8.

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: 25e159ba6dbe ("block, bfq: honor already-setup queue merges")
Signed-off-by: Jens Axboe <axboe@kernel.dk>