i40e: remove a stray unlock

i40e: remove a stray unlock

Orabug: 24568124

We shifted the locking around a bit but forgot to delete this unlock so
now it can unlock twice.

Fixes: cd3be169a5ff ('i40e: Move the mutex lock in i40e_client_unregister')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit be0cb0a66a1d426f7cd9b170c008725044ae147a)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>