Revert "block: fix request_queue->flags initialization"

This reverts commit 2101aa5b which is
commit 60ea8226 upstream.

To quote Ben:
	This is not needed, as there is no QUEUE_FLAG_BYPASS in 3.0.y.

To quote Tejun:
	I don't think it will break anything as it simply changes
	assignment to |= to avoid overwriting existing flags.  That
	said, any patch can break anything, so if possible it would be
	better to drop for 3.0.y.

So I'll revert this to be safe.

Cc: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

block/blk-core.c

@@ -524,7 +524,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
 	q->request_fn		= rfn;
 	q->prep_rq_fn		= NULL;
 	q->unprep_rq_fn		= NULL;
-	q->queue_flags		|= QUEUE_FLAG_DEFAULT;
+	q->queue_flags		= QUEUE_FLAG_DEFAULT;
 
 	/* Override internal queue lock with supplied lock pointer */
 	if (lock)