iavf: don't clear a lock we don't hold

In iavf_configure_clsflower() the function will bail out if it is unable
to obtain the crit_section lock in a reasonable time. However, it will
clear the lock when exiting, so fix this.

Fixes: 640a8af5

 ("i40evf: Reorder configure_clsflower to avoid deadlock on error")
Signed-off-by: Nicholas Nunley <nicholas.d.nunley@intel.com>
Tested-by: Tony Brelinski <tony.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>