afs: Remove erroneous seq |= 1 in volume lookup loop

afs: Remove erroneous seq |= 1 in volume lookup loop

The `seq |= 1` operation in the volume lookup loop is incorrect because:
seq is already incremented at start, making it odd in next iteration
which triggers lock, but The `|= 1` operation causes seq to be even
and unintended lockless operation

Remove this erroneous operation to maintain proper lock sequencing.

Fixes: 32222f09782f ("afs: Apply server breaks to mmap'd files in the call processor")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/20260622090856.2746629-9-dhowells@redhat.com
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>