RDMA/uverbs: Initialize udata struct on destroy flows

Cited commit introduced the udata parameter to different destroy flows
but the uapi method definition does not have udata (i.e has_udata flag
is not set). As a result, an uninitialized udata struct is being passed
down to the driver callbacks.

Fix that by clearing the driver udata even in cases where has_udata flag
is not set.

Fixes: c4367a26

 ("IB: Pass uverbs_attr_bundle down ib_x destroy path")
Cc: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Co-developed-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>