The object lock was supposed to always be released during destroy, but
when the destruction retry series was integrated with the destroy series
it created a failure path that missed the unlock.

Keep with convention, if destroy fails the caller must undo all locking.

Fixes: 87ad80ab ("IB/uverbs: Consolidate uobject destruction")
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>