ice: remove the VSI info from previous agg

Remove the VSI info from previous aggregator after moving the VSI to a
new aggregator.

Signed-off-by: Victor Raj <victor.raj@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>