IB/core: Fix missed clean call in registration path

In case of failure returned from query function in
IB device registration, we need to clean IB cache which
was missed.

This change fixes it.

Fixes: 3e153a93 ('IB/core: Save the device attributes on the device
structure')
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>