i40e: remove unnecessary i variable causing -Wshadow warning

Commit c61c8fe1

 ("i40e: Implement an ethtool private flag to stop
LLDP in FW") added an extra for-loop which added a shadowing 'i'
variable as the index.

However, the local variable i already exists, and we already use it as
a loop index. Additionally, at this point, there is no further use of
the variable, so it's safe to simply overwrite the variable contents.

This fixes a -Wshadow warning which has started being enabled on some
distributions

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Patryk Malek <patryk.malek@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>