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>