When destroy_* is called as a result of uverbs create cleanup flow a
cleared udata should be passed instead of NULL to indicate that it is
called under user flow.

Fixes: c4367a26 ("IB: Pass uverbs_attr_bundle down ib_x destroy path")
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>